COMPTONIA COMPTONI. 69 



Gtats— COMPTONIA, Gray. 



Gray, 1840. Annals and Magazine of Natural History, vol. vi, p. 278. 

 — 1866. Synopsis of Starfishes in the British Museum. 



Body depressed, with produced tapering rays. Disc covered abactinally and 

 actinally with numerous polygonal plates which possess a uniform granulation. 

 Marginal plates numerous. Supero-marginal plates equal in number to the infero- 

 marginals, and forming a moderately broad border to the disc. Infero-marginal 

 plates (as well as all other plates) devoid of spines. Radialia present throughout 

 length of ray. 



This genus apparently differs from Stellaster only in the absence of spines on 

 the infero-marginalia. It is thus similar to, as well as prior to Ogmaster (von 

 Martens, 1865) and Dorigona (Gray, 1866). 



1. Comptonia Comptoni, Forbes, sp. PL XVII, figs. 3, 3«, and 3 5; PI. XVIII, 



figs. 2, 2 a, 2 b, 2 c, 2 d. 



Stellaster comptoni, Forbes, 1848. Mem. Geol. Surv. Gt. Brit., vol. ii, p. 476. 



■ — Forbes, 1850. In Dixon's Geology and Fossils of the 



Tertiary and Cretaceous Formations of Sussex, 

 pi. xxii, fig. 8, p. 335. 

 — Dujardin et Hupr, 1862. Hist. Nat. Zooph. Echin. (Suites 



a Buffon), p. 408. 

 — — Forbes, 1878. In Dixon's Geology of Sussex (new edition, 



Jones), pi. xxii, fig. 8, p. 368, 370. 



Specific Characters. — Disc large and interbrachial arcs wide, giving the disc a 

 distinctly pentagonal appearance. Major radius rather more than twice the length 

 of the minor radius. Arms elliptical in cross section. Large valvate pedicellariae 

 present. 



Material. — Two specimens (the two cotypes) of this species are in existence. 

 One (formerly in the Bowerbank Collection) displays the actinal aspect (PI. XVII, 

 fig. 3), and is preserved in the British Museum of Natural History (34311). 

 The other (PI. XVIII, fig. 2), which shows the dorsal aspect, is preserved in the 

 Northampton Museum. This is the specimen figured in Dixon. 



Description. — The large pentagonal disc is covered dorsally with numerous 



