Scientific Serials

Abstract

THE Quarterly Journal of Microscopical Science for March contains:—On a new species of Phymosoma, with a synopsis of the genus, and some account of its geographical distribution, by Arthur E. Shipley (Plate xi.). The new species, P. weldoni, was found by Prof. Weldon at Bimini Island, the Bahamas; it has no trace of hooks on the introvert; there are two retractors. A synopsis of the twenty-seven species now known is given, but seventeen species are described in Selenka's monograph on the Sipunculidæ. As to the geographical distribution, seventeen species are found in the Malay Archipelago, of which thirteen are endemic, five are found in the Red Sea, four in the Mauritius, and three are found in the West Indies, but P. lovenii is found only in the Bergen Fiord.—On the British species of Crisia, by Sidney F. Harmer (Plate xii.). The author thinks that the ovicells furnish satisfactory specific characters; the aperture in the ovicell is also an important character. Specific diagnoses of C. denticulate, Lmk., C. eburnea, Linn., C. aculeata, Hass., and C. ramosa, n. sp., are given. Notes are given of the habit of the Zoarium at different seasons, on the mode of branching, and on the breeding-times.—The later larval development of Amphioxus, by Arthur Willey (Plates xiii.-xv.). The author again visited Messina, in the summer of 1890, to complete his studies on the development of the atrial chamber of Amphioxus. As a possible explanation of the asymmetry of the larva, Willey thinks that it can be traced ultimately to the adaptive forward extension of the notochord, being thus a purely ontogenetic phenomenon; the club-shaped gland is shown to be a modified gill-slit. —On the structure of two new genera of earthworms belonging to the Eudrilidæ, and some remarks on Nemertodrilus, by Frank E. Beddard (Plates xvi.-xx.). Hyperioadrilus africanus, n. gen. and sp., and Heliodrilus lagosensis, n. gen. and sp., found in a Ward case from Lagos, at Kew Gardens.