PuatTE 36. 
1-3. Colobocentrotus Mertensii Brandt. 
1. Seen from the actinal side. 
2. The same seen from the abactinal side. - 
3. The same specimen, seen in profile, facing the bivium and odd posterior interam- 
bulacrum. 
All figures are natural size. 
Bonin Ids., Captains Ringgold and Rodgers, N. P. Ex. Ex., Dr. Wm. Stimpson Coll. 
