CLARK : THE CIDARIDAE. 227 



Porocidaris elegans. 



Porocidaris elegans A. Agassiz, 1879, Proc. Amer. Acad., 14, p. 198. 



Plate 3, Challenger Ech., A. Agassiz, 1881. 



Originally collected by the " Challenger " off New South Wales and southeast 

 from the Philippines, specimens of Porocidaris, referred to this species, have since 

 been taken by the " Valdivia " near Sumatra, and off the east coast of Africa, and 

 by the " Siboga " among the Dutch East Indies. One of the specimens collected 

 by the latter vessel measured 85 mm. h. d. The specimen from the Bay of Biscay 

 reported by Koehler ('96) is doubtless not this species ; but probably purpura ta, 

 though it might be sharreri, with which species elegans agrees in coloration and 

 many other points. The 5 specimens taken by the " Siboga " which de Meijere 

 (:04) calls " Cidaris elegans juv. ?" are rather peculiar, especially the pedicel- 

 lariae, and their real relationship is doubtful. The specimens taken by the 

 " Valdivia " differ from elegans, not only in their remarkably light coloration, but 

 in their small abactinal system, actinostome and anal system, the very thorny 

 primaries, and their large number of coronal plates. It is quite likely that they 

 are a distinct species. 



Porocidaris misakiensis. 



Cidaris (Porocidaris) misakiensis Yoshiwara, 1898, Ann. Zodl. Jap., 2, pt. 2, p. 58. 

 Plate 2, fig. 16, Siboga-Exp. Ech., de Meijere, 1904. 



This is the most dubious species of the genus, especially as no complete de- 

 scription or figures have appeared. Aside from the original preliminary descrip- 

 tion, the only available information about misakiensis is contained in de Meijere's 

 " Siboga" report (:04). He found one specimen which might be referred to this 

 species, but the difference between it and elegans is difficult to understand, and it 

 will be surprising if the two prove to be really distinct. Yoshiwara's specimen was 

 39 mm. h. d., and de Meijere's was 50 mm. The color is said to be dark brown. 



Porocidaris cobosi. 



Porocidaris cobosi A. Agassiz, 1898, Bull. M. C. Z., 32, 5, p. 74. 



Plate 9, Pan. Deep Sea Ech., A. Agassiz, 1904. 



This is the handsomest species of the genus, and except purpurala, the easiest 

 to recognize. It has been taken only once, and then by the " Albatross," near 

 Chatham Island, Galapagos, on a rocky bottom in 3S5 fths. The largest specimen 

 is only 35 mm. h. d. 



