122 FIFTEENTH REPORT ON THE CABINET OF NAT. HISTORY. 



POTERIOCRINUS YERTICILLUS ( n. s.). 



Body elongate, clavate or subfusiform ; the height to the top of the 

 first radial plates equal to twice the greatest transverse diameter. 

 Easal plates elongate, about twice as high as wide, gradually 

 expanding from below; their upper ends obtusely pointed. Sub- 

 radials half as high again as wide, three hexagonal and two hep- 

 tagonal. First radials half as large as the subradials, a little wider 

 than high, pentagonal and hexagonal. Second radials, or first 

 arm-plates, small, little more than half as wide as the first radials, 

 quadrangular. Four anal plates are preserved in the specimen; 

 the first small, quadrangular, resting obliquely upon two sub- 

 radials, and its upper margins placed against the lower lateral 

 angles of a first radial and the second anal plate : second and 

 third anals larger, resting between the first radials of the adjacent 

 rays; fourth one small, about equal to the second radials, and 

 resting directly on the top of the third anal plate. Arms unknown. 



Surface of plates smooth or finely granulose. Column round, of 

 medium size, composed of rather strong plates, which are some- 

 what unequal near the junction with the body. 



This species is closely related to F.fusiformis of the Burlington lime- 

 stone, in general form and structure, but differs in the proportions of the 

 plates, especially of the first arm-plates, which in that species are very 

 long. 



Geological formation and locality. In the shales of the Hamilton group: 

 Ontario county. C. A. White, collector. 



POTERIOCRINUS INDENTUS ( n. s.). 



Body less than medium size, broadly calyculate or subturbinate, 

 gradually spreading to the top of the first radials. Basal plates 

 low, less than one-fourth of the entire height of the cup, very 

 obtusely pointed at the upper end. Subradials proportionally 

 large, height and breadth subequal; three hexagonal and two 

 heptagonal, the latter largest. First radials of moderate size, a 

 little wider than high, pentagonal, with the upper angles bent 

 inward, giving them the appearance of being heptagonal. Cicatrix 

 for the arm-attachment extending two-thirds across the plate. 

 Four anal plates preserved; the first one is largest, pentagonal, 

 resting between two subradials and the first radial plates : second 

 anal plate smaller, resting on the top of the largest subradial; 

 third and fourth anal plates small. 



