Cuticular Bars Research Articles

Fine structure of the tracheoles of the lantern of a photurid firefly.

The lantern tracheoles of the firefly, Photuris, are unusual in that their walls are reinforced by cuticular bars. The tracheoles are stiff and resist collapse under conditions which flatten more typical tracheoles. This reinforcement and the structural resemblance of the tracheal end cell to cells considered to be active in moving ions and fluid is taken as evidence suggesting that the flash may be turned on and off by control of the oxygen supply and that said control may involve some sort of osmotic mechanism.

Die feinstruktur der fl�igelschuppen einiger Lycaeniden (Insecta, Lepidoptera)

Green, blue and violet colours of Lycaenidae examined by us — with the exception of Rapala arata (Theclinae) — are due to iridescent scales which are arranged before a dark background. The iridescent scales are constructed according to the Urania-type and may be diverted from pigmented scales by laying in equidistant lamellae and little cuticular bars, which maintain the distance between the lamellae. The ribs in the longitudinal axis of the scales contain lamellae and bars only in the Plebejinae, in Lycaeninae and Theclinae they are small and sit on the plain upperside of the scale with a narrow base.

Studies on Monogenetic Trematodes. VI. Two New Dactylogyrid Genera from Florida Fishes

The genus Anchylodiscus was proposed by Johnston and Tiegs (1922) to receive A. tandani, the type species, from the gills of Tandanus tandanus. The only other species (A. gadopsis) of this genus was described by Hughes (1928) from the gills of Gadopsis sp. Both of these parasites are from Australian hosts. A careful examination of a species of Tetraonchinae from the gills of the robalo (Centropomus undecimalis ) from Florida waters, reveals characters sufficient to place it in a genus distinct from its two nearest morphological relatives listed above. Anchylodiscus species are devoid of body spines and possess relatively short cuticular bars which are individual whereas the species from C. undecimalis has body spines which take origin as far forward as the copulatory complex and in addition possesses two very long bars (the longest being over twice as long as the longest anchor) which are articulated with each other in their midregions. It appears that this combination of characters together with host-parasite relationships are sufficient for generic distinction. An exclusvely fresh-water genus, Actinocleidus Mueller, 1937, of Tetraonchinae also possesses articulated cuticular bars. In this group, however, the bars are much modified, both pairs of anchors occur on the same side of the haptor, and the intestinal crura are confluent with each other on or near the peduncle.