216 PALJEONTOLOGY OF NEW-VORK. 



Genus CARYOCRINUS (Say). 



" Column cylindrical, perforated by a tubular alimentary canal : pelvis formed of four plates ; 

 " costals six, supporting the scapulae, from which the arms proceed. 



" In Miller's arrangement, this genus will occupy a station in the division Inartir.ulata, 

 '■ between the Genera Cyatiiocrinites and Actinocrinites. It may be indicated by the fol- 

 " lowing formula : 



A. Pelvis of four plates. 



A. Costal plates six. 



a. Column not diladed. 



o. Alimentary canal. 



^. Articulating surface of the columnar joints, radiated. 



t. Auxiliary side-arms cylindrical, and placed irregularly. Geims Caryochinites. 



1. Two of the costals hexagonal. \st Sp. ornatus. 



2. One of the costals hexagonal. 2/id Sp. loricatus." 



601. 1. CARYOCRINUS ORNATUS. 



Pl. XLIX. Fig. 1 a-2 ; and PL. XLIX A. Fig. la-<i. 



CaTyocrinites ornatus. Say, Jour. Acad Nat. Science, Vol. iv, p. 289, 1825. 



C. loricatus. Id. 



C. ornatus. Loodon Zoological Journal, October 1825, p. 291. 



— — Blainville, Man. d'Aclinologie, pag. 263, pl. 29, fig. 5, 1843. 



— — Cabtei.nau, Essai sur le Systeme Siluricn de I'Amerique septcntrionale, 



pl. 25, fig. 2, 1843. 



— — Hall, Rep. 4th Gcol. Dist. N. York, pag. Ill, fig. 1 & 2, & p. 112, 1843. 



Column round, composed near the body of larger and smaller joints alternating with each 

 other ; edges of the joints thin and sharp, sometimes slightly crenulated or denticulated ; ar- 

 ticulating surfaces having the striaj extending from the margin half way to the centre ; canal 

 round. Body ovoid or more or less subglobose, the greatest diameter being usually below the 

 middle ; summit slightly convex, and surrounded by a corona of arms and fingers, varying in 

 number, and extending to the length of several inches ; body composed of three series of plates ; 

 pelvic or basal plates four, two of them pentagonal and two hexagonal ; costal plates six, large, 

 forming more than half the height of the body, two of these are pentagonal, two are hexagonal, 

 and the other two hcptagonal ; scapular plates six, alternating with the costal plates ; inter- 

 scapular plates two, resting on the truncated upper sides of the heptagonal costal plates ; the 

 upper edges of the scapular and interscapular plates are interrupted and made irregular upon 

 their upper margins by the arms, the lower joints of which rest on their indented edges. The 

 summit presents the appearance of a depressed arch or dome, composed of numerous plates 



