596 Contributions to Invertebrate Palaeontology, 



FOSSII.S FROM THE COAL MEASURES. 



ECHINODERMATA. 

 CRINOIDEA. 



Genus CYATHOCRIIVUS Miller. 



Cyatliocriiius Soinersi. 



Plate XV, figs. 4 and 5. 



Cyathocrims Somersi Whitf., Ann. N. Y. Acad. Sci., 1882, p. 226. 



Calyx very shallow, being low and spreading ; the extreme height to the top 

 of the first radial plates not exceeding one-fonrth of the diameter ; the sides, 

 above the middle of the subradial plates, gradually and almost evenly curving. 

 Centre of the calyx below deeply impressed, the cavity embracing the basal 

 and inner half of the subradial plates. Basal plates very small, extending 

 but little beyond the circumference of the proportionally small column, and 

 forming by their union a somewhat regular pentagon. Subradial plates of 

 medium size, four of them being equal, and pointed at their upper ends, the 

 upper edges being convex ; the fifth plate is larger than the others, and is 

 truncated above by the very small first anal plate, which rests between the 

 adjacent first radials, and lias apparently joined three other plates above. 

 Tlie surface of this plate bears a single round granulose tubercle. First radial 

 plates nearly twice as wide as high ; their lateral faces being short and uniting 

 with those of the adjacent plate, except on the anal side, where they are 

 separated by the first anal plate. Articulating face for the second radials 

 nearly straight, but deeply grooved. Second radial plates short ; that of the 

 anterior ray being cuneiform above, and has supported an arm-plate on each 

 upper sloping surface. The second radials of the other rays have not been 

 fully determined ; but on the antero-lateral rays, where partially detached 

 plates remain, they have been quadrangular, as if for the support of other 

 radial plates in a direct series. Surface of the inner half of the subradial 

 plates smooth, while the outer half and the entire surface of the other plates 

 are covered with proportionally laig(!, distinct, irregular tubercles, which are 

 flattened on their surfaces and covered with numerous small, distinct grannies. 

 The granules also extend to parts of the intermediate surface. The upper 

 margin of the first radial is bounded by an elevated transverse ridge, which is 

 also granulose. 



This species bears considerable resemblance in its jjeneral surface- 

 marking's to Eupachycrinus tubercalatus M. and W. (Geol. Surv. 



