THE CRICOID HYPOCRINUS. 



907 



The greatest width of each basal is at about two-thirds of its 

 height, and here also the sides slope equably to a prominent 

 umbo, above which the plates bend towards the oral pole, the 

 bend being more sudden on the left than on the right. 



The Radials (PL XO. fig. 9 ; text-fig. 160) continue the slope of 

 the upper part of the basals. They present several abnormalities 

 due to growth, and are further obscured by crushing. Only four 

 were distinguished by Dr. Rothpletz, but I believe I can see 

 traces of a fifth, though much atrophied [and this is fully con- 

 firmed by Dr. Wanner in litt."\. Ant. R and 1. ant. R were 



RR 



Text-fig. 160. 



•---r.p.Rr- 



BB 



IBB 



" Hvpocrinus " piriformis. 

 Analysis of the cup of the holotype. 



The sutures obscui-ed by wear or fracture are represented in dotted line, 

 as is also the outline of the periproct. 



r.p.R denotes the minute plates, of rather uncertain number and shape, one or all of 

 which probably represent this radial. On I.p.B the outline of the cleaved 

 surface is represented. The outline of a.R is modified bi" a slight shear. 

 Nat. size. 



apparently of less modified outline than the others, though in 

 this specimen weathering and crushing have rendered that out- 

 line incomplete. The 1. ant. R rests on 1. ant. B by a longer 

 side than that which rests on 1. post. B. Similarly, the side of 

 ant. R, resting on the r. ant. B seems to have been longer than 

 that on 1. ant. B. Ant. R is broken, and part of it, still united 

 to 1. ant. R has been pushed inwards and under the remaining 

 portion. Thus it is difiicult to compare the interradial sutures 

 bounding these two radials, but there is nothing to show that 

 they were not of equal length. The upper margin of each of 

 these radials was excavated by a concave curve, and the edge 



