24 BULLETIN 64, UNITED STATES NATIONAL MUSEUM. 



Pelvis, [base] sub -pentagonal divided into 3 unequal parts. 



Body, composed of four [five], irregularly shaped, externally convex pieces, form- 

 ing, connected together, a hemispherical cup, with a broad border, having a tooth-like 

 elevation on one side and on the opposite side a lanceolate depression. 



Supplementary description. — The essential characteristics of the 

 genus are as follows: Basals three, unequal, projecting beyond the 

 column on the left anterior side. There are five dissimilar radials of 

 which the anterior and left posterior radials are fan-shaped, much 

 larger than the others, and bear numerous (15 to '31) arms each. The 

 arms are unbranched and non-pinnulate. The right posterior radial 

 bears a tooth on which the anal tube rests. No anal plate is present. 



Genotype. — Catillocrinus tennesseese. 



The first published description of the genus was by Shumard 

 [1868, p. 357]. He described the calyx erroneously as made up of 

 three series of plates, and assumed that the basal pieces were prob- 

 ably five in number. Wachsmuth and Springer [1886, p. 268] and 

 Bather [1900, p. 150] describe the basal disk as undivided, but 

 Troost' s observation appears to be correct, as the suture lines between 

 the plates show distinctly on one of the specimens, and traces of them 

 appear on others. 



CATILLOCRINUS TENNESSEE.® (Shumard). 



Plate 9, figs. 1, 2, 3. 



Catillocrinites tennesseese Troost, Proc. Amer. Ass. Adv. Sci., II (read 1849), 



1850, p. 60 (nomen nudum); MSS., 1850. 

 Catillocrinus tennesseese Shumard, Trans. Acad. Sci. St. Louis, II, No. 2, 1866, 



p. 358. — Wachsmuth and Springer, Rev. Palseocrinoidea., Ill, 1885, p. 



272. — Miller, North Amer. Geol. and Pal., 1889, p. 231 (catalogue name). 



The original description by Troost is as follows: 



The plates which compose the body are — a pelvis [base] which is an irregular 

 pentagon more or less concave, bearing a circular impression for a column which oc- 

 cupies almost the whole of the pelvis [base] and has an irregular pentagonal or penta- 

 petalous aperture. The margins of the articulating surfaces of the column are notched. 

 This pelvis supports two irregular semilunar plates and four [two] irregular pear-shaped 

 plates of which one seems to be divided into two parts [i. e. five* plates in all]. The 

 superior border being irregularly circular, occupying more than half of the whole 

 superior surface, is covered with radiating striae, somewhat like the articulating 

 surfaces of the encrinital columns — These striae proceed from a series of pores near 

 the external margin of the border and terminate partly in the abdominal cavity and 

 partly on the border itself as is shown in the figure. The striae above mentioned are 

 interrupted by a dental elevation. It is placed (the dental elevation) upon one of the 

 divisions of the above mentioned divided pear-shaped plate. Opposite to this dental 

 elevation and on the interior of the undivided pear-shaped plate is an aperture, or 

 furrow, occupying the space only of one pore on the external margin, but then extend- 

 ing, inwards and downwards, assuming a heart-shaped figure in the abdominal* cavity. 

 (See fig. 1.) The external surface, the pelvis excepted, is finely granulated. 



Observations. — The six specimens of this species in the Troost collec- 

 tion represent the dorsal cup only. The form and proportions of the 



