REPORT ON THE CRINOIDEA. 197 
XII.—DESCRIPTION OF THE SPECIMENS. 
Class CRINOIDEA. 
Order NEocRINOIDEA. 
Family Hotorip®, Roemer, 1856 ; emend. Zittel, 1879, and P. H. Carpenter, 1884. 
Genus, Holopus, dOrbigny, 1837 ; emend. P. H. Carpenter, 1884. 
A. GeneraL Account oF THE TYPE. 
Definition.—Basals and radials completely anchylosed into an asymmetrical tube- 
like calyx, which is fixed by an irregularly expanded base. On the upper edge of the 
cup are five unequal articular surfaces for the attachment of the second radials. Arms 
ten, massive, and closely inrolled. Disk relatively small, with a central mouth pro- 
tected by five oral plates, between which and the edge of the cup is a very narrow irregular 
pavement of smaller plates. Anus probably present, but not yet observed. 
Remarks.—The description of this genus, which was established by d’Orbigny in 
1837, attracted much attention on account both of the novelty and of the rarity of this 
singular type. The specimen described by d Orbigny? which was for a long time unique, 
was brought from Martinique by M. Sander Rang. It is tetra- instead of penta-radiate 
as most Crinoids are, and this seems to have caused some misconception respecting its 
true nature, for it receives no mention whatever in Pictet’s Paléontologie; while 
Dujardin and Hupé* expressed their opinion in 1862 that Holopus is not a Crinoid at 
all, but an altogether different type, probably a Cirripede.* 
A few years later, however, a normal pentaradiate example was brought up on a 
fisherman’s line from deep water off Barbados. It was fortunately acquired by the 
governor, Sir Rawson Rawson, and was placed by him in the hands of Prof. Louis Agassiz 
during the stay of the “ Hassler” at Barbados in 1872. Prof. Agassiz intended to have 
published a full description of the specimen, but was prevented from doing so by failing 
health, and after his death the figures which he had prepared were published by 
Mr. Alexander Agassiz, together with a short descriptive note by Count Pourtalés.’ 
1 Mémoire sur une seconde esptce vivante de la famille des Crinoides ou Encrines, servant de type au nouveau 
genre Holope (Holopus), Guérin, Mag. de Zool., Tme année, Classe x., § pp., pl. 8, Paris, 1837. 
2 Op. cit., p. 218. 
3 Description of a Specimen of Holopus rangii from Barbados, Mem. Mus. Comp. Zodl., vol. iv. No. 8, p. 51. 
. 
