﻿WOOD] new and old middle devonic crinoids 7 1 



DOLATOCRINUS ASTERIAS n. sp. 



I l'i vit. XVI. i, i,;. ) 



Description. — Dorsal cup low and broad; sides vertical, base flat- 

 tened, with a deep and narrow basal indentation which includes a 

 little more than half of the radials. Plates very thick, with the suture 

 lines usually deeply impressed, though this is a variable feature, and 

 in some specimens the depressions are not strongly marked. 



Surface highly ornamented. In the most typical specimens the 

 ornament consists of sharply elevated ridges which pass from the 

 center of each plate to the middle of its sides. These ridges are 

 stronger on the radials and first interbrachials, forming a star-shaped 

 figure whose points are at the middle of the interbrachials. At these 



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Fig. 5. — Dolatocrinus asterias n. sp. Arrangement of calyx plates. 



points there is usually a circular depression, though occasionally a 

 low node replaces the depression. Other ridges from the center of 

 the radials outline the basal depression, forming a five-sided rim 

 around it. The ridges of the higher calyx plates are nearly as dis- 

 tinct as those of the radials and first interbrachials. The ornament 

 of the surface, while always strongly marked in well-preserved 

 specimens, varies considerably in general appearance on different 

 individuals. On some specimens the center of each plate, where the 

 ridges intersect, is elevated, giving the surface a nodose rather than 

 a ribbed appearance. These varieties of ornament are readily seen 

 to belong to the same type, the differences being dependent mainly 



