I30 



NEW YORK STATE MUSEUM 



for a trace of external thickening shown on a few interradial lines 

 and designating their position. 



Basals five; a depressed distal surface about one fourth of the 

 area of the plate bears about i6 very fine, slightly rough, uniform 

 and parallel ridges which are set at right angles to the edge of 

 the plate and cross over the suture and on to the interradials ; 

 from their common suture to this depressed portion there are about 

 24 similar lines running also at right angles to the edge of the 

 plate and crossing over the suture and on to the radials ; the prox- 

 imal fourth of the plate is bent rather suddenly upward to form 



Fig. 8 At the left is a reproduction of a photograph of the exterior of a basal portion cf 

 Archaeocrinus? delic a»t u s. The fine, parallel, ornamental lines of the plates are lost 

 in the reduction save in part in one plate to the right where they had been strengthened a little 

 with a fine pen. At the left is a view of the inner surface of the same specimen. Most of the 

 sutures have been lined with ink. The infrabasals appear flat and ringlike in the figure but 

 they really form a deep cup with angled edges and with the plates apparently grown together 

 to form one piece. 



a portion of the basal concavity, between this bend and the middle 

 area there is a raised stronger ridge like a V with very widely 

 open arms, the angle turned away from the basal crater and thus 

 forming a portion of a basal pentagonal ridge. 



The radials are similarly ornamented with the fine lines, from 

 8 to 12 to the mm, which are set at right angles to the sutures. 

 The radials are completely separated by large interradials without 

 any supplementary plates. The anal interradial has an extra plate 

 and gives an additional angle to the radial of 1. post. R. The 

 cup has a rather wide and somewhat flattened base, the distance 

 across at level of outer suture of the radials measuring about 

 16 mm. 



