784 THE CRINOIDEA CAMEEATA OF NORTH AMERICA. 



of four or five moderate sized plates, followed by a very large number 

 of small pieces, forming an elongate, convex area, which rises from the 

 large anal plate, and extends to the posterior oral, being surrounded on all 

 sides by a shallow groove. The plates of the area, although irregular in 

 form, are arranged with a certain regularity, and the lower ones are con- 

 siderably larger than those surrounding the anal opening, which are very 

 minute. The anus i.s located in the upper part of the area, and opens out 

 laterally. Column small and round. 



Horizon and Locality. — Upper part of St. Louis group ; Franklin Co., 

 Ala., and Tateville, Pulaski Co., Ky. 



Ti/jM in the Shumard collection at the Museum of Washington University, 

 St. Louis. 



Talarocrinus sexlobatus (Shum.). 

 Plate LXXVIII. Figs, la, h, c. 



1856. Dickocrinns sexlobatus — Shujiakd; Trans. St. Louis Acad. Sci., Vol. I., p. ?3, Figs. 3, Za-c. 



1865. Pterotocrhms sexlobatus — SnusiiED; Catal. Palteoz. Foss. N. Amer. p. 39i. 



1867. Pterotocritius sexlobatus — S. A. Millek; Catal. Amer. Palaoz. Foss. (1st Edit.), p. 89. 



1881. Talarocrinus sexlobatus — W. and Sp. ; RevisioQ Palseocr., Part 11., p. 87. 



18S3. Talarocrinus sexlobatus — S. A. Miller; Catal. Amer. Palffioz. Foss. (2d Edit.), p. 288. 



Calyx a little higher than wide, constricted at the arm regions, and 

 surmounted by five short heavy spines. Dorsal cup more depressed than 

 in the preceding species, the plates more rapidly spreading and more tumid, 

 making the outline of the cup, as seen from below, quite distinctly six-lobed. 

 The plates devoid of ornamentation. 



Basal cup shallow, its height from a side view less than one fourth the 

 length of the radials; the salient angles at the upj)er margin very obtuse, 

 as are also the re-entering angles toward the anal plate and anterior radial; 

 the centre slightly excavated for the reception of the column. Radials about 

 as wide as long, widest at two thirds their height, very thick and tumid in 

 the middle ; their greatest convexity is near the upper end, whence they 

 slope rapidly to the arm bases, forming a rounded, transverse node. The 

 lower faces in four of the radials are straight, or nearly so, in the anterior 

 one obtusely angular ; all the superior faces are deeply excavated, and their 

 outer ends project somewhat like the limbs of the radials in Blastoids. The 

 anal plate is longer than the radials, and, like them, tumid near the top and 

 widest across the middle. Costals very small, not visible externally, being 

 perfectly covered by the distichals. Distichals comparatively large, resting 



