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 ina row. The color is gray or whitish, 
sometimes marked with darker gray or brown. (Plate LV.) 
Genus Ophiocoma 
O. riisei, O. eethiops, O. Alexandri. 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. riiset is 
found at Key West, the other two species on the coast of Lower 
California. (Plate LV.) 
GENUS Ophiothria 
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.) * 
