APPENDIX. 341 



the passage to the genus Pandasia, but has a series of 

 sunken minutely porous spaces in the place of the upper 

 marginal plates. 



Randasia, Gray, 



Body pentagonal, depressed, minutely granular. Back 

 nearly flat, minutely granular, reticulated ; reticulations 

 rather tubercular; interspaces sunken (when dry), and 

 covered with very minute close perforations. Dorsal tuber- 

 cles, roundish, single, subcentral ; margins furnished with 

 an upper and lower series of oblong ossicules, the upper 

 one narrower internally, with a central series of tubercles, 

 the lower ones oblong, close together, and convex. The 

 oral surface protected by close regular squareish convex 

 ossicules, covered with short crowded granules. The 

 ambulacral spines in rounded groups, the series of tubercles 

 nearest the ambulacra larger, crowded, and placed in groups 

 of three or five, and those in the oral angles largest and flat- 

 topped. 



This genus differs from Pentaceros in the back being 

 flat, and not angularly elevated ; it is, in several respects, 

 intermediate between Culcita and Pentaceros. 



Randasia granulata, n. s. 



Body 5-sided, back minutely granular, with roundish 

 convex subconical tubercles on the reticulations ; the mar- 

 ginal plates 14 on each side, the upper ones with a central 

 series of tubercles. 



Inhab. — Reefs of Atagore, N. Australia. 



There are two specimens of this species in the British 

 Museum, one in a very bad state. 



Randasia spinulosa, n. s. 

 Body 5 -sided, back and upper marginal plates covered 



