216 MARINE INVERTEBRATES 



in length and thread-like in size. These long, slender arms have, on 

 both the upper and under surfaces, a row of overlapping plates, and are 

 fringed with small spines, three in a row. The color is gray or whitish, 

 sometimes marked with darker gray or brown. (Plate LV.) 



GENUS Ojthiocoma 



O. riisei, O. cethiops, O. Alevcandri. These animals have long 

 spines on the sides of the arms, which give them a bushy appearance. 

 The surface of the body is granulated, but the arms are covered with 

 wide plates. Their color is brown above and light beneath. 0. riisei is 

 found at Key West, the other two species on the coast of Lower 

 California. (Plate LV.) 



GENUS Ophiothrioc 



O. angulata. Body covered with short, rough spines ; egg-sacs 

 conspicuous and extend like lobes between the arms ; rays narrow and 

 thickly beset with long spines, which are serrated on the edges and ends. 

 Found on the Florida coast. (Plate LV.) 



