258 Annals of the South African Museum. 



plates of both surfaces justifies regarding them as different species. 

 Ahactinally these plates in capensis are noticeably larger, especially 

 in the midradial line, and they carry more granules within the 

 marginal circle, than in attstraliensis, while actinally the reverse is 

 true, the actinolateral plates of capensis rarely having more than one 

 central granule while in australiensis there are almost always 2-5. 

 The papulae in capensis are noticeably larger and more regularly 

 arranged than in australiensis. In this particular, capensis is more like 

 ornatus Fisher of Hawaii, but the differences in the actinolateral plates 

 and adambulacral armature prevent any confusion with that species. 

 The specimens from 18183 are smaller than those from 18230 but 

 they are like them in all essentials and call for no special comment. 



CERAMASTER CHONDRISCUS *, sp. nov. 

 Plate XIV. Figs. 5, 6. 



R = 52 mm.; r = 30 mm.; R. = 1'7 r. Interbrachial arcs very 

 broadly round ; the interradial margins of the body are almost per- 

 fectly straight; rays well marked and rather abruptly projecting. 

 Abactinal plates tabulate, completely granulated; the six primary 

 plates are easily seen as the largest tabulae; otherwise the largest 

 tabulae are at the center of the disk and on the median line of the 

 basal half of each ray ; these larger tabulae are more or less perfectly 

 hexagonal, but the plates of the proximal part of each interradial 

 area are more rhomboidal (in the holotype, they are perfectly rhom- 

 boidal) or pentagonal or irregular; distally in the interradii the plates 

 become very small, and are roughly oblong or hexagonal; the sides 

 of the tabulae are very straight, their marginal granules being sharply 

 cut vertically on the outer side; on the larger tabulae there are 

 about 20 marginal and about 25 central granules, all closely crowded. 

 In the holotype and the smallest specimen, one or several of these 

 granules are, on a few tabulae, replaced by large, bivalved, often 

 excavate pedicellariae ; on the third specimen, these are remarkably 

 abundant. 



Supermarginal plates 16-18 (17 in the holotype) on each side of 

 each ray. Those in the interradii are nearly or quite square and 

 there are only 6 or 7 on the basal half of the ray, as against 10 or 

 11 on the outer half; the distalmost three or four are however very 

 short and this increase in number is no doubt correlated with the 

 relatively long rays. The bare area, which in some species of 

 Ceramaster may occupy the whole abactinal surface of the plate, is 



= a granule, in reference to the numerous abactinal granules. 



