248 Annals of the South African Museum. 



by the presence of an epiproctal cone and the absence of pedicellariae, 

 but Verrill has shown that both these features are youthful and 

 quite unreliable. In the present series, there is no epiproctal cone in 

 the large specimen, but it is obvious in all the small ones; it is 

 however smallest in the smallest specimen (1 mm. high) and largest 

 (3 mm.) in a specimen with R = 17 mm. Apparently therefore 

 it reaches its fullest development in late youth and then disappears, 

 but is still evident in specimens one-third grown. The terminal 

 plate is but very little larger in the big specimen than in the smallest 

 and has entirely lost the three conspicuous spines which it bears in 

 youth. The adambulacral plates are relatively considerably longer in 

 the adult but the adambulacral armature changes but little, as there 

 are 3 spines in the smallest specimen and only 5 in the big one. 

 There is no indication of a supermarginal spinelet in the smaller 

 specimens but in the largest it is evident on a dozen plates or more 

 in each series; it is however remarkably low and squamiform. 



P.F. 16742. Cape Point N. E. x E. J /4 E., 38 miles. 755 fms. 

 Green mud. 1 specimen; adult. 



P.F. 16902. Cape Point N. E. x E. '/ 4 E., 40 miles. 800-900 fms. 

 Green mud. 2 specimens; young. 



P.E. 17351. Cape Point N. 83 E., 43 miles. 900-1000 fms. Green 

 mud. 2 specimens; young. 



PSILASTER ACUMINATUS. 



Sladen, 1889. CHALLENGER Ast., p. 225; pi. 40, figs 1, 2. 



It is not without some hesitation that I refer these specimens to 

 Sladen's species, for in one particular they are very different from 

 his description. He says the marginal plates are more or less bare 

 (lower part of superomarginals, upper part of inferomarginals) and 

 covered by a membrane, while in the African specimens, papillae 

 cover the plates; along the margins the papillae are slender but on 

 the surface of the plates they are quite squamiform. In one specimen, 

 the lower portion of the largest superomarginals is only sparsely 

 covered with papillae so perhaps if the specimens were larger these 

 plates would be bare. But in these specimens, R 60 mm. + and 

 Sladen's type had R only 65 mm. 



Another difficulty is that these specimens are so unlike a much 

 larger Psilaster from Australia which in my ENDEAVOUR report I have 

 called aciiminalus, that it is hard to believe they are the same 

 species. Sladen however called attention to differences between the 

 African, Australian and New Zealand specimens of the CHALLENGER 



