358 TRANS. OF THE ACAD. OF SCIENCE. 



CATILLOCRINUS, Troost (continued). 



Tennesseea3 3 t Troost, 1850. List Crin. Tenn. Proc. Amer. Assoc. 

 Camb. Meet, p. GO. — Arch. — Button-mould Knob, 7 miles 

 south of Louisville, Kentucky ; White's Creek Springs, 

 Tennessee. 



CHE1R0CRINUS,J Hall, 1859. 



(Calceocrinus?) chrysalis, Hall, 1859. 13th Rep. Reg. State Cab. 



N. York, p. 123, fig. 1-5.— Mag New York. 



(Calceocrinus?) clarus, Hall, July, 1862. 15th Rep. Reg. State 

 Cab. New York, p. 116, pi. 1, fig. 17.— Ham.— Ontario Co., 

 New York. 



(Calceocrinus?) dactylus, Hall, 1859. 13th Rep. Reg. State Cab. 



N. York, p. 123, fig. 1-3 on p. 24 — Erie. — Burlington, Iowa. 

 (Calceocrinus?) lammellosus, Hall, 1859. 13th Rep. Reg. State 



Cab. N. York, p. 123.— Enc— Burlington, Iowa. 

 (Calceocrinus?) nodosus, Hall, 1859. 13th Rep. Reg. State Cab. 



N. York, p. 124.— Arch. 



(Calceocrinus?) perplexus,*? Shumard, n. sp. — Arch. — Button- 

 mould Knob, Kentucky. 



t Catillocrinus Tennesseece, Troost. 



Description.— Cup hemispherical, width one and a half times greater 

 than the height, composed of thick pieces firmly united together; surface 

 thickly studded with small granulse and marked with strong sulci at the 

 sutures, which impart to the cup an irregularly lobed appearance. Base 

 (concealed by the column) small, pentagonal, situated in a dgep cavity and 

 projecting into the interior in form of a low cone. Primary radials form- 

 ing united an irregular pentagon, with curved margins which scarcely rise 

 above the plane of the under surface of the cup, almost entirely concealed 

 by the last joint of the column. Secondary radials, very irregular in form, 

 thick, convex; two very large, transverse, forming about two thirds the 

 cup, expanding rapidly from below upwards so as to embrace nearly the 

 whole of the superior circumference ; between these on one side are wedg- 

 ed in two of the smaller pieces, one of them quadrangular with nearly par- 

 allel sides, the other linguaBform, and opposite these is a large quadrangu- 

 lar piece with sides converging from below upwards. The upper surfaces 

 of this series of pieces are marked with numerous sharply-impressed, curv- 

 ed, radiating sulci, each of them pierced with a minute aperture at the 

 points of attachment for the arms. 



I have had a number of specimens of this very curious Crinoid since 1845. 

 They were found at Button-mould Knob, seven miles south of Louisville, 

 Kentucky, in blue marls and marly limestones, which I suppose to be of 

 the age of the Keokuk division of the Archimedes Limestone. They were 

 found associated with Actinocrinus Yandelli, Calceocrinus perplexus, Pro- 

 ductus semireticulatus, and Chonetes Shumardianu. Dr. Troost's specimen, 

 which I saw during the year 1847 in Nashville, was found, in rocks of the 

 same geological age, at White's Creek Springs, Tennessee. 



X We strongly suspect that Cheirocrinus is identical with Calceocrinus 

 proposed by Prof. Hall in 1852. Comparing the figure of the basal por- 

 tion of Calceocrinus, in the supplement plate at the end of the 2d volume 

 of the Palaeontology of New York, with that of Cheirocrinus tunicatus, in 

 the 13th Report of the Regents of the State Cabinet of Natural History, we 

 perceive, at least, a very striking similarity of structure. 



§ Cheirocrinus (Calceocrinus?) perplexus. 



Description. — This species is much larger than any described by Prof. 

 Hall. The pieces are moderately robust, and the surface thickly studded 

 with small but distinct granules. The basal plate in some examples at- 

 tains a width of more than an inch, and a height of from one third to one 

 fourth of an inch: the pieces composing it are firmly anchylosed; the dor- 



