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 H.M.S. '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. Annobon, Gulf of Guinea, 18-30 m. 12 specimens. 



