120 Dr. J. E. Gray on Echinoderms collected hy 



spicules on the surface ; these vary a little in shape at the 

 end. 



A very young specimen, apparently of the same species, is 

 brown, and the spines brown and white-ringed ; the spines are 

 quite clear, and covered with longitudinal series of rather large 

 rounded tubercles. The spines vary in shape : they are 

 generally cylindrical and truncated j but a few are fusiform 

 and tapering to a point. 



Cidaris ornata (Gray, P. Z. S. 1855, p. 37) is perhaps a 

 variety. 



Echmothrix Desorii^ Bolsche, Archiv fiir Naturgesch. 1865, 

 p. 330. 

 Astropyga Desorii, Agassiz, Ann. Sci. Nat. 1846, p. 34o. 



Hah. Red Sea. 



Diadema Savignn, Michelin, Mag. Zool. ; Agassiz, A. R. 

 p. 349 ; Dujard. & Hupe, Echin. p. 505 ; Savigny, Echin. 

 Egypte, t. 6 ; Bolsche, Arch, fur Naturg. 1865, p. 227. 



Cidarites mamillata, And. p. 109. 

 Jun. D. Lamarckii, Agassiz. 

 Echinothrix calamaris, Petei's. 



tiircariim, Peters, Bolsche. 



Garetia turcarum, Agassiz. 



Diadema Dujardinii, Michelin, Mag. Zool. 1845, t. 7. 



Var. 1. The spines of the oral surface white. 

 Vm\ 2. Spines all pale. 



Hah. Red Sea. 



See : — Diadema [Echinothrix) calamare^ Martens, Wiegm. 

 Arch. 1866, p. 150. Echinus calamarius^ Pallas, Spic. Zool. 

 X. p. 38, t. 2. f. 4-8; Gmelin, Syst. Nat. p. 3173. Cidaris 

 calamarius, Leske, Lamk., Gray ; Michelin, Rev. Zool. p. 14, 

 no. 26. Astropyga calamaria, Agassiz. 



The shell is covered with small black spines. The upper 

 part of the shell has a broad, smooth area, radiating from the 

 anal opening, as in Astropyga. The spines are very slender, 

 tubular, and covered externally with whorls of short, regular, 

 closely packed, adpressed spines. The spines near the oral 

 region are slender, subcylindrical, striated, slightly depressed, 

 and clavate at the end. 



I have not seen any specimen with such long slender spines 

 as that figured in the great work on Egypt. In all I have 

 seen the spines were thicker compared with their length, and 

 much shorter compared witli tlio diameter of the body. 



