394 Dr. J. E. Gray on Holopus and Pentacrinus. 



of shields from head to dorsal. Tail tetrahedral. tapering, 

 terminating in a moderately large caudal fin. The top surface 

 is considerably broader than the lower one; it has alx)Ut 

 thirty-four rings, of Avhich about sixteen are occupied by the 

 egg-pouch in males. The dorsal stands on seven tail-rings, 

 and equals the length from extremity of snout to anterior of 

 opercles, measured on the lower surface of the head ; it has 

 twenty-six rays. The lateral line joins the upjjcr surface of 

 the tail at the end of the dorsal fin. Colour : blackish, Avith 

 more or less regular series of white points, brown spots, and 

 irregular patches. 



Length 4^ inches. 



Numerous specimens were found at the confluence of the 

 Cued Cherif and the died Bou-llamdan, in the province of 

 Constantine (twelve miles above Guelma, and sixty miles from 

 the sea). 



XL VIII. — Notes on Holopus and Pentacrinus. 

 By Dr. J. E. Gray, F.K.S. 



Mr. Rawson W. Rawson, C.B., the Governor of Barbadoes, 

 has kindly sent me the following observation : — " I have 

 procm*ed a specimen of a Penta- 

 crinus from the north of the 

 Island of Barbadoes, dredged or, 

 rather, picked up in about -"» 

 fathoms Avater. I enclose a 



■)] 



sketch (see figure). It is ink- 



black, a portion broken so as to 

 show the interior of the contracted 

 armlets and the Pentacrinal 

 formation of the mouth or en- 

 trance of the central canals. Do 

 you know Avhat it is? I am 

 under the impression of liaving 

 seen an engraving of such a zoo- ^ 



phyte, but cannot find it." 



There can be no doubt that the animal here referred to is 

 very similar to the crinoid described by M. d'Orbigny at the 

 Academic des Sciences, Feb. 27, 1S37. The paper is printed 

 at length in the ' Magasin de Zoologie ' for the same year, 

 witli a plate, under the name of Holopus liaixju'. 



There is a short notice of the characters oi' the genus in the 

 ' Aniuiles des Sciences Naturelies,' vol. viii. |). 123, and in 

 VViegmann's ' Arcliiv ' for 1830. 



