Subgeneric Rank Research Articles

Analytic taxonomy and notes on marine, brackish-water and estuarine Gastrotricha

Marine Gastrotricha, both Macrodasyida and Chaetonotida, are the subject of an analytic review, citing taxonomic status of names, authorships of taxa, and those responsible for changes, in accordance with the International Code of Zoological Nomenclature, 4 th ed. (1999). Notes are included with regard to taxonomic usage so as to guide workers in the future. Among the proposed novelties are: within Macrodasyida, to restrict the family Lepidodasyidae Remane, 1927 to the genus Lepidodasys Remane, 1926, and to establish a new family, Cephalodasyidae with Cephalodasys Remane, 1926 as its type-species to house the remaining genera and species that have been contained in the polyphyletic family Lepidodasyidae. Hemidasys agaso Claparède, 1867 is considered extinct, and the new name Tetranchyroderma antenniphorum is proposed for Tetranchyroderma antennatum Luporini, Magagnini & Tongiorgi, 1973; in addition, five species are here considered to be species inquirendae: Dactylopodola weilli d'Hondt, 1965, Paradasys nipponensis Sudzuki, 1976, Macrodasys indicus Kutty & Nair, 1969. Tetranchyroderma forceps d’Hondt & Balsamo, 2009 and Turbanella plana (Giard, 1904b). Among Chaetonotida: the Xenotrichula velox-species group Ruppert, 1979 and the Xenotrichula intermedia-species group Ruppert, 1979 were given each the rank of subgenus. Chaetonotus pleuracanthus Remane, 1926 is rejected as a synonym for Chaetonotus marinus Giard, 1904; Chaetonotus somniculosus Mock, 1979 is transferred to the genus Halichaetonotus, the new name Halichaetonotus euromarinus is proposed for Halichaetonotus spinosus Mock, 1979, and Xenotrichula carolinensis Ruppert, 1979 is re-established. Heteroxenotrichula variocirrata d'Hondt, 1966 is here considered to be species inquirenda.

In praise of subgenera: taxonomic status of cobras of the genus Naja Laurenti (Serpentes: Elapidae)

The genus Naja Laurenti, 1768, is partitioned into four subgenera. The typical form is restricted to 11 Asian species. The name Uraeus Wagler, 1830, is revived for a group of four non-spitting cobras inhabiting savannas and open formations of Africa and Arabia, while Boulengerina Dollo, 1886, is applied to four non-spitting African species of forest cobras, including terrestrial, aquatic and semi-fossorial forms. A new subgenus is erected for seven species of African spitting cobras. We recommend the subgenus rank as a way of maximising the phylogenetic information content of classifications while retaining nomenclatural stability.

Taxonomic and nomenclatural notes on freshwater Gastrotricha

Some taxonomic and nomenclatural remarks concerning freshwater species of Gastrotricha Chaetonotida are presented. In the family Chaetonotidae, the subgenus Chaetonotus (Hystricochaetonotus) is synonimized with the subgenus C. (Chaetonotus sensu stricto). The genus Lepidochaetus is moved to a subgeneric rank into the genus Chaetonotus, and the subgenus Nudichaetonotus Schwank, 1990 is synonymized with C. (Lepidochaetus). Chaetonotus (Lepidochaetus) brasilianus is proposed as a replacement name for Chaetonotus brasilense Kisielewski, 1991, which has become a secondary junior homonym of Chaetonotus brasiliensis Schwank, 1990. Emended diagnoses of the genus Chaetonotus and of the subgenera C. (Chaetonotus sensu stricto), and Chaetonotus (Lepidochaetus) are given. The 3 subgenera of the genus Ichthydium introduced by Schwank (1990) have not been introduced in the present list. In the family Dasydytidae, the subgenus Dasydytes (Setodytes) is synonymized with the genus Setopus. Six new species by Schwank (1990) (Aspidiophorus ontarionensis, Chaetonotus (C.) furculatus, Chaetonotus (Zonochaeta) annae, Ichthydium malleum, Lepidodermella forficulata and Dasydytes (Setodytes) lemnicola) are nomina nuda. An updated list of the reliable world freshwater species of Gastrotricha is reported.

Phylogeny and biogeography of bees of the tribe Osmiini (Hymenoptera: Megachilidae)

The Osmiini (Megachilidae) constitute a taxonomically and biologically diverse tribe of bees. To resolve their generic and suprageneric relationships, we inferred a phylogeny based on three nuclear genes (Elongation factor 1-α, LW-rhodopsin and CAD) applying both parsimony and Bayesian methods. Our phylogeny, which includes 95 osmiine species representing 18 of the 19 currently recognized genera, is well resolved with high support for most basal nodes. The core osmiine genera were found to form a well-supported monophyletic group, but four small genera, Noteriades, Afroheriades, Pseudoheriades and possibly Ochreriades, formerly included in the Osmiini, do not appear to belong within this tribe. Our phylogeny results in the following taxonomic changes: Stenosmia and Hoplosmia are reduced to subgeneric rank in Hoplitis and Osmia, respectively, Micreriades is recognized as a subgenus in Hoplitis and the subgenus Nasutosmia is transferred from Hoplitis to Osmia. We inferred a biogeographic scenario for the Osmiini applying maximum likelihood inference and models of character evolution. We provide evidence that the Osmiini originated in the Palearctic, and that extensive exchanges occurred between the Palearctic and the Nearctic. The latter finding may relate to the fact that many osmiine species nest in wood or in stems, facilitating dispersal by overseas transport of the nests.

Taxonomic revision of Hawaiian Bembidion Latreille (Coleoptera: Carabidae: Bembidiini) with a discussion of their reductive and derivative evolutionary specializations

The Bembidion fauna (Coleoptera: Carabidae: Bembidiini) of the Hawaiian Islands is taxonomically revised, entailing the recognition of 23 native, precinctive species, and one adventively introduced Old World species, Bembidion niloticum Dejean. Two species previously placed in Gnatholymnaeum Sharp—G. blackburni Sharp, 1903, and G. spurcum (Blackburn, 1881)—are formally placed as member taxa within Bembidion Latreille, with Gnatholymnaeum recognized at subgenus rank. This taxonomic placement establishes Bembidion blackburni Csiki, 1928, as a junior secondary homonym, and Bembidion ateradustum, new name, is proposed as a replacement. Twenty-one species are recognized as member taxa of Bembidion subgenus Nesocidium Sharp, five of which are newly described: Bembidion waialeale, new species, from Kauai; Bembidion paratomarium, new species, and Bembidion gagneorum, new species, from Oahu; Bembidion kamakou, new species, from Molokai; and Bembidion haleakalae, new species, from East Maui. Bembidion molokaiense Sharp (new synonymy) is treated as a junior synonym of Bembidion ignicola Blackburn, and Metrocidium brevicolle Sharp (new synonymy) is placed as a junior synonym of Bembidion munroi (Sharp). Taxonomic treatment includes a key to species, diagnoses and descriptions of the male genitalia and female reproductive tract for all species, and complete descriptions of external characters for newly described species. Length of the male aedeagal flagellum in subgenus Nesocidium species was found to be subequal in length, to 60–75% longer than the female spermathecal duct, consistent with previous reports that list emplacement of the male spermatophore within the female spermathecal duct as a primary function of the male flagellum. Geographical distribution varies in concert with dispersal ability. All species including at least some individuals with fully developed flight wings are distributed on multiple oceanic islands. Representative taxa within putative clades of vestigially winged species occupy adjacent oceanic islands, implying overwater dispersal by wingless ancestors of present-day species followed by speciation. Ecological preference conforms to the taxon cycle at the archipelago level, with the ancestor of Hawaiian Bembidion hypothesized to have inhabited coastal habitats. Present-day ecological specialists include a deep-soil inhabitant, and numerous species found predominantly in arboreal microhabitats such as mossy vertical tree trunks and horizontal nurse logs. Geographic distributions of the species define areas of endemism appropriate for conservation that are geographically congruent with areas defined by other carabid beetle taxa in Blackburnia Sharp and Mecyclothorax Sharp, as well as by taxa in other insect groups.

Review of the genus Ceraturgus Wiedemann (Diptera: Asilidae) in North America north of Mexico

The species of Ceraturgus occurring in the eastern United States and Canada are reviewed. A key to species, descriptions, illustrations of wings and some genitalic features, and distribution maps are presented. Ceraturgus fasciatus is resurrected from synonymy with Ceraturgus cruciatus, and Ceraturgus mabelae is reduced to synonymy with Ceraturgus nigripes (new synonymy). Ceraturgopsis is resurrected, assigned subgeneric rank, and Ceraturgus cornutus is fixed as type species. This work is dedicated to the memory of one of America’s foremost asilidologists, Joseph Wilcox.

Phylogeny and classification of Ochlerotatus and allied taxa (Diptera: Culicidae: Aedini) based on morphological data from all life stages

The phylogenetic relationships and generic assignments of ‘Ochlerotatus’ and related taxa of uncertain taxonomic position in the classification of Aedini previously proposed by the authors in 2004 and 2006 are explored using 297 characters from eggs, fourth-instar larvae, pupae, adults and immature habitat coded for 158 exemplar species. The ingroup comprises 54 species and the outgroup includes four non-aedine species and 100 aedine species, 21 of which were previously classified as incertae sedis. Data are analysed in a total-evidence approach using implied weighting. The analysis produced 158 most parsimonious cladograms. The strict consensus tree (SCT) corroborates the monophyly of the 30 generic-level taxa recognized previously that are included in the analysis. Overall, the results show remarkable congruence with those obtained previously despite differences in the taxa and morphological characters analysed in this and the two previous studies. All species of Ochlerotatus s.s., subgenus ‘Ochlerotatus’sensu auctorum, Geoskusea, Levua, Pseudoskusea and Rhinoskusea included in the analysis fall within a single clade that is treated as genus Ochlerotatus; thus, the last four taxa are restored to their previous subgeneric rank within this genus. Nine additional subgenera, of which four are new, are proposed for monophyletic clades of Ochlerotatus species based on the strength of character support and application of the principle of equivalent rank. Acartomyia stat. nov., Culicelsa stat. nov., Gilesia stat. nov., Protoculex stat. nov. and Chrysoconops stat. nov. are resurrected from synonymy with Ochlerotatus; and Empihals subgen. nov. (type species: Culex vigilax Skuse), Pholeomyia subgen. nov. (type species: Aedes calcariae Marks), Buvirilia subgen. nov. (type species: Aedes edgari Stone & Rosen) and Sallumia subgen. nov. (type species: Aedes hortator Dyar & Knab) are described as new. The sister group of Ochlerotatus includes a number of species that were previously regarded as incertae sedis in ‘Oc. (Finlaya)’ and ‘Oc. (Protomacleaya)’. Based on previous observations, refined relationships and new character support, three additional genera are recognized for species previously included in ‘Finlaya’, i.e. Danielsia stat. nov. (type species: Danielsia albotaeniata Leicester), Luius gen. nov. (type species: Aedes fengi Edwards) and Hopkinsius gen. nov. (type species: Aedes ingrami Edwards). Additionally, Alloeomyia subgen. nov. (type species: Culex pseudotaeniatus Giles) and Yamada subgen. nov. (type species: Aedes seoulensis Yamada) are introduced as subgenera of Collessius and Hopkinsius, respectively. As is usual with generic-level groups of Aedini, the newly recognized genera and subgenera are polythetic taxa that are diagnosed by unique combinations of characters. The analysis corroborates the previous observation that ‘Oc. (Protomacleaya)’ is a polyphyletic assemblage of species. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 153, 29–114.

Phylogeny and classification of Finlaya and allied taxa (Diptera: Culicidae: Aedini) based on morphological data from all life stages

The phylogenetic relationships and generic assignments of ‘Ochlerotatus’ and related taxa of uncertain taxonomic position in the classification of Aedini previously proposed by the authors in 2004 and 2006 are explored using 297 characters from eggs, fourth-instar larvae, pupae, adults and immature habitat coded for 158 exemplar species. The ingroup comprises 54 species and the outgroup includes four non-aedine species and 100 aedine species, 21 of which were previously classified as incertae sedis. Data are analysed in a total-evidence approach using implied weighting. The analysis produced 158 most parsimonious cladograms. The strict consensus tree (SCT) corroborates the monophyly of the 30 generic-level taxa recognized previously that are included in the analysis. Overall, the results show remarkable congruence with those obtained previously despite differences in the taxa and morphological characters analysed in this and the two previous studies. All species of Ochlerotatus s.s., subgenus ‘Ochlerotatus’sensu auctorum, Geoskusea, Levua, Pseudoskusea and Rhinoskusea included in the analysis fall within a single clade that is treated as genus Ochlerotatus; thus, the last four taxa are restored to their previous subgeneric rank within this genus. Nine additional subgenera, of which four are new, are proposed for monophyletic clades of Ochlerotatus species based on the strength of character support and application of the principle of equivalent rank. Acartomyia stat. nov., Culicelsa stat. nov., Gilesia stat. nov., Protoculex stat. nov. and Chrysoconops stat. nov. are resurrected from synonymy with Ochlerotatus; and Empihals subgen. nov. (type species: Culex vigilax Skuse), Pholeomyia subgen. nov. (type species: Aedes calcariae Marks), Buvirilia subgen. nov. (type species: Aedes edgari Stone & Rosen) and Sallumia subgen. nov. (type species: Aedes hortator Dyar & Knab) are described as new. The sister group of Ochlerotatus includes a number of species that were previously regarded as incertae sedis in ‘Oc. (Finlaya)’ and ‘Oc. (Protomacleaya)’. Based on previous observations, refined relationships and new character support, three additional genera are recognized for species previously included in ‘Finlaya’, i.e. Danielsia stat. nov. (type species: Danielsia albotaeniata Leicester), Luius gen. nov. (type species: Aedes fengi Edwards) and Hopkinsius gen. nov. (type species: Aedes ingrami Edwards). Additionally, Alloeomyia subgen. nov. (type species: Culex pseudotaeniatus Giles) and Yamada subgen. nov. (type species: Aedes seoulensis Yamada) are introduced as subgenera of Collessius and Hopkinsius, respectively. As is usual with generic-level groups of Aedini, the newly recognized genera and subgenera are polythetic taxa that are diagnosed by unique combinations of characters. The analysis corroborates the previous observation that ‘Oc. (Protomacleaya)’ is a polyphyletic assemblage of species. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 153, 29–114.

Phylogeny and New Intrageneric Classification of Allium (Alliaceae) Based on Nuclear Ribosomal DNA ITS Sequences

The internal transcribed spacer region (ITS) of nuclear ribosomal DNA was sequenced from 195 representative species of Allium, two species of Nothoscordum, and one species each of Ipheion, Dichelostemma, and Tulbaghia. Within the Allium species the lengths of the ITS regions were in a range from 612 to 661 base pairs and pairwise genetic distances reached up to 46%. The ITS data supported the inclusion of Nectaroscordum, Caloscordum, and Milula into Allium. Subgenera Rhizirideum and Allium, as well as sects. Reticulatobulbosa and Oreiprason were non-monophyletic taxa. Based on the phylogenetic relations, a new classification of genus Allium consisting of 15 monophyletic subgenera is presented. Sections Microscordum, Anguinum, Porphyroprason, Vvedenskya, Butomissa, Cyathophora, and Reticulatobulbosa are raised to subgeneric rank. Sections Austromontana N. Friesen, Eduardia N. Friesen, Mediasia F. 0. Khassanov, S. C. Yengalycheva et N. Friesen, Nigrimontana N. Friesen, Falcatifolia N. Friesen, and Condensatum N. Friesen are newly described. Series Daghestanica, Pallasia, and Scabriscapa, as well as subsects. Eremoprasum, Longivaginata, and Sikkimensia are raised to sectional rank. A taxonomic conspectus of Allium at sectional level is given.

TWO NEW SPECIES OF BORAGINACEAE (TRIBE CYNOGLOSSEAE) FROM TURKEY

Two new species of Boraginaceae are described from Turkey: Paracaryum hedgei and Rindera dumanii. Their affinities and phytogeography are discussed. Both species are illustrated and their distributions mapped. Rindera sect. Bilegnum is raised to subgeneric rank as Rindera subgen. Bilegnum.

The subgeneric nomenclature for the herbaceous-stemmed Smilax species (Smilacaceae) of North America

Abstract The subgeneric nomenclature for the herbaceous-stemmed Smilax species (Smilacaceae) of North America. Brittonia 56: 166–168. 2004.—The several names and ranks given to the North American group of Smilax with biovulate locules together with both herbaceous and non-prickly stems are listed chronologically and discussed nomenclaturally. It is concluded that this group of approximately nine species should be known at the generic rank as Nemexia Raf. or at the rank of subgenus as Smilax subgenus Luiste Raf. or at section rank as Smilax section Nemexia (Raf.) A. DC.

Phylogeny of the Afro-Madagascan Aristea (Iridaceae) revisited in the light of new data on pollen morphology

Scanning and electron microscopic studies of the pollen grains of several species of the sub-Saharan African and Madagascan genus Aristea of c. 50 species, supplement data from an earlier study and enable us to include these species in a phylogenetic analysis. TEM examination of a range of pollen grains of representative pollen types in Aristea makes it possible to reinterpret past SEM results so that apertures covered with exine masses and previously called sulculate, are now seen to be either zonasulculate or dizonasulculate. Revised and expanded data are combined in a matrix together with new data for seed morphology in the genus, which like the capsules is remarkably diverse, including angular seeds with reticulate sculpturing, lamellate or triangular-columnar seeds with smooth or reticulate surfaces and with smooth or papillate or areolate margins. This new phylogenetic analysis suggests that Aristea should remain treated as comprising three subgenera. In subgenus Eucapsulares we add a new section Latifolieae for A. latifolia, which seems an isolated relic restricted to the mountains of the Cape Region of South Africa, an area of winter rainfall. Species with similar unspecialized capsule and seed morphology occur only in eastern south and tropical Africa and Madagascar, but they have derived pollen morphology whereas the pollen of A. latifolia is plesiomorphic. This species appears to be the closest living ancestor of the genus. In subgenus Aristea we continue to recognize three sections, sect. Racemosae, sect. Singulares and sect. Aristea. Nesting of subgenus Pseudaristea within section Racemosae of subgenus Aristea is probably an artefact of the analysis and does not receive bootstrap support, and hence we continue to recognize this group of species at subgeneric rank. © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society, 2004, 144, 41–68.

Two new species of the orientalis group of Rheocricotopus (Psilocricotopus) from China (Diptera: Chironomidae)

Rheocricotopus (Psilocricotopus) calviculus sp. n. and R. (P.) villiculus sp. n. from China are described as male imagines. The species are closely related to the previously described R. (P.) orientalis Wang forming a new group, the orientalis group, which eventually may deserve the rank of subgenus or even genus. The group is distinguished by lacking a humeral pit, numerous sensilla clavata on third palpomere, cuneiform wings, no or few setae on squama, long legs, banded abdomen, very long inferior volsella, gonocoxite with apical extensions, and gonostylus with a median triangular projection.

Jurassic Gastropod Faunas of Central Saudi Arabia

ABSTRACTMapping of Phanerozoic rocks at 1:250,000 scale by joint teams from the Saudi Arabian Deputy Ministry for Mineral Resources and the Bureau de Recherches Géologiques et Minières since 1980 has covered most of the Jurassic outcrops in central Saudi Arabia. Stratigraphic, sedimentologic and paleogeographic studies provided a precise framework for collected gastropod faunas that could be calibrated against ammonite zones and sequence-stratigraphic zones. Of more than 600 samples collected, about 440 gastropod specimens could be determined on at least a generic level. Their age range is from Bajocian to Oxfordian–Kimmeridgian. They correspond to 26 genera and 35 species from the Euomphalidae, Ataphridae, Pseudomelaniidae, Coelostylinidae, Procerithiidae, Nerineidae, Purpurinidae, Aporrhaidae, Naticidae, Acteonidae, Retusidae, and Akeridae families. Twelve species are new, and three (Kosmomphalus and Bifidobasis in the Euomphalidae, and Striatoonia in the Pseudomelaniidae) were proposed for new taxa of generic or subgeneric rank. Most of the identified species are of Middle Jurassic age, mainly Bathonian and Callovian and only six are Late Jurassic. All species are typical of an internal platform environment (upper infralittoral), in a lagoonal to back-reef setting, but some also colonized the external platform in the lower infralittoral fore-reef zone. Paleogeographically, most of the species are related to European and Sinai faunas; only seven are equivalent to North African or East African faunas, and one only was reported from Madagascar.

Cimicicapsus Poppius a separate genus, with description of new species (Heteroptera: Miridae)

as a distinct genus, was recently demoted to subgeneric rank within Deraeocoris Kirschbaum, 1855 by Kerzhner & Schuh (1995). However, their treatment remains questionable because polyphyly of the genus Deraeocoris was frequently suggested (e. g. Schuh 1995) and its subgeneric classification is therefore problematic. In the present paper, three East Asian species of Cimicicapsus are reported, and the taxonomic status of the genus is discussed. All measurements are given in millimeters. Material examined, including types, is deposited in the National Institute for Agro-Environmental Sciences, Tsukuba, Japan, except for several specimens, where the name of depository follows the specimen’s data.

Revision of the genus Genlisea (Lentibulariaceae) in Africa and Madagascar with notes on ecology and phytogeography

The African and Madagascan representatives of the carnivorous genus Genlisea are investigated. All African material belongs to subgenus Genlisea and can be assigned to 10 taxa, which mainly differ in indumentum of calyx, corolla and ovary. The former section Tayloria, restricted to South America, is raised to subgeneric rank. One species, Genlisea margaretae, occurs in South‐East Africa and Madagascar as well. All species are restricted to specific oligotrophous habitats like granitic outcrops (inselbergs), ferricretes, white sands and swamps. Genlisea taylori from Angola is described as new. All species are described and illustrated and a key and distribution maps are presented.

Phylogeny of Anophelinae (Diptera Culicidae) Based on Morphological Characters

Phylogenetic relationships of mosquitoes in the subfamily Anophelinae are presented based on a cladistic analysis of 163 morphological characters from females, males, fourth-instar larvae, and pupae of 64 species. Species examined include one Chagasia Cruz, three Bironella Theobald, and 60 species representing all six subgenera of Anopheles Meigen. Uranotaenia lowii Theobald and Aedeomyia squamipennis (Lynch Arribalzaga) are used as outgroups. This analysis indicates that Anophelinae is monophyletic, that Chagasia is the earliest-diverged lineage within Anophelinae, and that the genus Anopheles, as currently defined, is paraphyletic because it excludes Bironella. Four nonhomoplastic synapomorphies support the monophyly of the clade composed of the genera Bironella and Anopheles. Three major lineages are recognized within this clade. The basal lineage (lineage 1) contains An. (Nyssorhynchus), An. (Kerteszia), and An. implexus (Theobald). This analysis supports the monophyly of the sister groups Nyssorhynchus Blanchard and Kerteszia Theobald, but finds the Albimanus, Argyritarsis, and Myzorhynchella sections of the subgenus Nyssorhynchus to be paraphyletic. The second lineage (lineage 2) contains species of the subgenus Cellia Theobald, which is monophyletic. Except for the Cellia series, however, all other series of the subgenus Cellia are paraphyletic. The third lineage (lineage 3) contains species of the subgenera Anopheles Meigen, Stethomyia Theobald, Lophopodomyia Antunes, and of the genus Bironella. Bironella and Stethomyia are monophyletic sister groups. The Lophoscelomyia and Arribalzagia series are monophyletic. The Arribalzagia and Cycloleppteron series are sister groups nested within the Myzorhynchus series. We conclude that there is no support for the generic recognition of Bironella, nor the subgeneric rank of Lophopodomyia and Stethomyia.

A CRITICAL APPRAISAL OF MODERN GENERIC CONCEPTS IN LICHENOLOGY

After a brief historical survey, some current trends in the delimitation of lichen genera are discussed. A widespread tendency is that of elevating any supposedly monophyletic group of species to genus rank. As the term ‘monophyletic’ has no lower limit, this is likely to result in an explosive inflation of new genera, in a severe loss of the information carried by generic names and in a high degree of nomenclatural disorder. Five criteria are proposed for the acceptance or rejection of new generic segregates: (1) DNA testing for monophyly, (2) phylo-genetic analysis, (3) number of characters used, (4) number of species considered, (5) information content of the new splittings. Upon a critical analysis of several recent generic segregations, a more flexible approach to taxonomic ranks is recommended, and particularly, when most of the suggested criteria are not fulfilled, a more frequent use of the subgeneric rank, which does not imply name changes.

Ultrastructure and relationships of spermatozoa of the freshwater crabs Potamon fluviatile and Potamon ibericum (Crustacea, Brachyura, Potamidae)

The spermatozoa of Potamon fluviatile and P. ibericum are virtually indistinguishable and do not support separate subgeneric rank (Potamon and Pontipotamon, respectively). Synapomorphic with the spermatozoa of the South African freshwater crab Potamonautes perlatus Sidneyi are the elongation of the two centrioles and disposition of the centrioles almost parallel to each other, unknown elsewhere in the Brachyura, and reduction of the thickened ring (homoplasic with grapsids and gecarcinids). Other, probably synapomorphic, similarities of Potamon and Potamonautes include the wide inner acrosome zone, absence of a definite acrosome ray zone (homoplasic in other families) and the cleistospermial spermatophores. Further similarities, of questionable polarity, are the simple, not multilaminar, nuclear membrane and the tendency of the nuclear arms to wrap around the nucleus. Differences of Potamon from Potamonautes, which possibly support their present generic separation and give weak support to their former separate familial placement in the Potamidae and Potamonautidae respectively, are perforation of the operculum and the weak, rather than strong, development of a periopercular rim. Absence in Potamon and Potamonautes of an accessory opercular ring and a xanthid ring separates them from xanthids. No close affinities with other heterotreme families are seen but their assignment to the Helerotremata is not in doubt. Their spermatozoa lack two of the distinctive features of thoracotreme spermatozoa (apical button on the operculum and concentric lamellation of the outer acrosome zone). No clear correlates of spermatozoon structure with a freshwater existence are recognizable but reduction of the thickened ring possibly relates to peculiarities of the acrosome reaction. However, the production of spermatophores with single spermatozoa (cleistospermia) is possibly a device to prevent polyspermy and wastage of the small number of lecithotrophic eggs produced in potamids.

Two New Species of Diospyros (Ebenaceae) from Mesoamerica

Diospyros hartmanniana, of cloud forests in Panama and Costa Rica, and Diospyros whitei, of lowland forests in central and eastern Panama, are described and illustrated. Their similarities to and differences from other Mesoamerican species of Diospyros are discussed. The genus Diospyros consists of approximately 500 species of small to large trees distributed throughout the tropics and subtropics of the world. The last worldwide revision of the family Ebenaceae was that of Hiern (1873), where some 250 species were recognized. Hiern recognized five genera, Royena L., Euclea Murray, Maba J. R. Forster & G. Forster, Tetraclis Hiern, and Diospyros L. In Diospyros s. str., Hiern recognized 14 sections defined on characters of the seed and inflorescence. Only a fraction of the approximately 80 New World taxa were included in Hiern's monograph. Bakhuizen van den Brink (1936), in monographing the Malaysian species of Ebenaceae, placed the genus Maba into synonymy with Diospyros at the rank of subgenus. He divided the Asian species of Diospyros into 36 sections, most of which are probably artificial (White, 1983). Royena and Maba are currently placed within the genus Diospyros s.l. (White, 1983), and Old World species previously regarded as Maba are placed in section Forsteria (Bakhuizen van den Brink) White. In his treatment of Ebenaceae for Flora Zambesiaca, White (1983) recognized 11 sections, most of which were endemic to Africa. Section Forsteria has several species in the New World and is defined by its possession of an ovary with three bi-ovulate locules. In Mesoamerica only D. inconstans Jacquin and D. salicifolia Willdenow are members of this group. For the rest of the taxa occurring in the Neotropics, no sectional classification has been proposed. In Asia, where some 200 species of Diospyros occur, the sectional classification proposed by Bakhuizen van den Brink (1936) has not been taken up in floras, and many species have been described relatively recently. In the course of preparing the treatment of Diospyros for Flora Mesoamericana the following new taxa were encountered. Diospyros hartmanniana S. Knapp, sp. nov. TYPE: Panama. Chiriquf: near Costa Rican border, ca. 13 road-km from Rio Sereno, Finca Hartmann, 1550-1750 m, 8?50'N, 82?45'W, 23 Oct. 1992, G. McPherson & P. M. Richardson 15959 (holotype, BM; isotypes, MO, PMA not seen). Figure 1. Species haec a Diospyros campechiana Lundell, foliis coriaceis petiolo breviori (6-9 mm longo vs. 10-20 mm longo), inflorescentia masculina tantum 3-5-flora, inflorescentia feminei uniflora, floribus carnosis, staminibus filamentis aureo-pubescentibus, baccis globosis, differt. Trees, 6-20 m; branchlets glabrous or minutely strigose with scattered black trichomes, drying shiny black, the buds coarsely and densely blackstrigose. Leaves 6-11 X 3-5 cm, elliptic, thick and coriaceous, glabrous above, sparsely strigose with scattered coarse black trichomes beneath, the trichomes denser near the veins, glabrescent, the young leaves densely black-strigose beneath, the trichomes breaking off and leaving black dots on the leaf undersides, the base acute, the margins somewhat revolute, the apex broadly acute, the ultimate tip rounded; lateral nerves 5-6 pairs, inconspicuous, the midvein drying darker beneath; petiole 6-9 mm, fleshy. Inflorescences axillary along the current growth. Male flowers in 3-4(-5)-flowered subsessile to shortly pedunculate cymules, the peduncle and bracts black-strigose, the pedicels ca. 0.5 mm; calyx 1.5-2 mm, fleshy, black-strigose without, glabrous within, drying black, the tube ca. 1 mm, flat, the lobes 5, ca. 1.5 mm, semiorbicular; corolla 4-5 mm, urceolate to somewhat salverform, glabrous throughout, drying black, the tube 3-3.5 mm, the lobes 4, ca. 1.5 mm, broadly deltate, the margins thinner and overlapping in bud; stamens ca. 10-12(-20), 1.5-2 mm (not including the elongate connective), densely golden pubescent, the connective long-apiculate; pistillode ca. 1 mm, black-strigose at the apex, otherwise glabrous. Female flowers (seen in young fruit only) solitary, sessile or nearly so, the pedicel 0-0.5 mm. Fruits 1.52.5 cm diam., yellow-orange when ripe, drying reddish brown, glabrous except for a patch of stiff black trichomes around the persistent style base; NovoN 7: 256-260. 1997. This content downloaded from 157.55.39.138 on Sun, 26 Jun 2016 06:12:47 UTC All use subject to http://about.jstor.org/terms Volume 7, Number 3 Knapp 257 1997 Mesoamerican Diospyros