Discovery reports (1936) Discovery reports discoveryreports12inst Year: 1936 286 DISCOVERY REPORTS evidently quite unusual; Fig. 22, a, b, show the more usual form. The second ventral plate is somewhat narrower than the following ones. These plates are slightly broader in the lower part, at the corners opposite the tentacle scales, than at the distal edge. The number of arm spines I find to be more generally six, sometimes only five. The species has separate sexes, the male gonads being particularly richly developed; they look rather like ovaries filled with eggs, but microscopical examinati
Discovery reports (1936) Discovery reports discoveryreports12inst Year: 1936 286 DISCOVERY REPORTS evidently quite unusual; Fig. 22, a, b, show the more usual form. The second ventral plate is somewhat narrower than the following ones. These plates are slightly broader in the lower part, at the corners opposite the tentacle scales, than at the distal edge. The number of arm spines I find to be more generally six, sometimes only five. The species has separate sexes, the male gonads being particularly richly developed; they look rather like ovaries filled with eggs, but microscopical examination shows at once their male character. The eggs are rather small and numerous, indicating that the species may have a typical Ophiopliiteiis larva. There is a rather considerable resemblance between this species and Amphiura Eiigeynae; but there can be no doubt that they are two quite distinct species. The absence Fig. 22. Amphiura princeps, Koehler. Part of oral side (a). Mouthparts of another specimen (b). Part of arm, dorsal side, joints ca. 20-23 ('')• -12. of the small outer mouth papilla, the very small inner ventral plate, and the generally larger number of arm spines in A. princeps, distinguish the two species very clearly, besides the fact that A. Eiigeniae is viviparous and apparently parthenogenetic, whereas A. princeps is evidently not viviparous and has separate sexes, the males being of common occurrence. Amphiura incana, Lyman Amphiura incana, Lyman, 1882. Sci. Results 'Challenger'. Ophiuroidea, p. 128, pi. xxxiii, figs. 5-7. A. incana, H. L. Clark, 1923. Echinoderm Fauna of South Africa. Ann. S. African Mus., xni, p. 328. A. incana. Hertz, 1926. Deutsche Siidpolar-Exped. Ophiuroiden, p. 34, Taf. vii, fig. i. A. incana, Mortensen, 1933. Echinoderms of South Africa. Papers from Dr Th. Mortensen's Pacific Exped., lxv (Vid. Medd. Dansk Naturh. Foren., 93), p. 351. St. 91. 23. ix. 26. False Bay, South Africa, 35 m. 6 specimens. St. 283. 14. viii. 27. Anno
Size: 1799px × 1112px
Photo credit: © Bookend / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
