126 



NEW YORK STATE MUSEUM 



Infrabasals completely concealed by proximal stem joints, basal 

 pit or depression 4 mm in diameter or but little more than the. 

 diameter of the stem joints which measure 3.5 mm. 



Basals with smooth transverse elevated ridge, angled on the plate, 

 making a pentagonal boundary to the basal concavity. There is 

 a transverse raised ridge near the outer edge of the plate, and 

 between this and the first there are three finer ridges the inner- 

 most of which meets the angle of the first mentioned ridge. Be- 

 tween this last finer ridge and the heavy transverse one the plate 

 is depressed, the inner angle of the radial is also depressed and 

 thus two basals and a radial unite to form a well marked depressed 



Fig. 6 Analysis of Hercocrinus elegans. The interradial areas are. shaded. The 

 one at the extreme left is likely to have some fractures represented as sutures. This side of 

 the theca was crushed in. The fourth interradial area from the left is the one to the front in 

 the upper figure of plate 9. The same interradial area is also the upper of the two interra- 

 dial areas in part shown in the right-hand portion of the lower figure. The rounded, gemlike 

 surfaces of the plates of these areas and the tendency to form small supplementary pieces is 

 well shown. 



triangular pit; , one basal, is marked by two short lines within this 

 pit, in the others it is smooth. The outermost of these plate ridges 

 crosses the suture and continues over the sides of the radials which 

 are slightly smaller than the exposed surface of the basals. This 

 marginal ridge is about .6 mm from the edge of the plate and marks 

 off an outer depressed, smooth and concave surface (the outer- 

 most edge of the radials being again slightly raised where they 

 meet the interradials). Some of the finer lines of the basals after 

 passing over the radials are continued up the brachials in an ir- 

 regular manner as a fine central line, with here and there others, 

 on a strongly convex medial space which otherwise would be re- 

 markably smooth. The brachials are also edged with a very smooth 

 concave border like that on the edsfe of the radials. 



