94 A. E. Verrill on Echinoderms and Corals 
above; its position varies from nearly vertical to decidedly 
oblique, and it is so nearly terminal as to produce a posterior 
emargination in a dorsal view of the shell. Ina side view some 
specimens are decidedly depressed, but most are regularly 
arched, while one is decidedly elevated at the apex. There is 
considerable variation in the depth of the anterior ambulacral 
groove, and also in the number and prominence of the large 
tubercles, which are more or less restricted to the region enclosed 
by the peripetalous fasciole. The fasciole itself shows remark- 
able variations, but does not agree at all with that of ML 
b 
pointing to the anal region, and another to the right of it, point- 
ing to the summit; in all the specimens it bends inward further 
able 
though indicated by a band of smaller tubercles, but in one 
een it is well marked and the subanal disk is 
erfectly 
Bilobed: narrowest in the middle, scarcel east alppedh be 
