PuLaTE 45. 
1-5. Colobocentrotus Stimpsoni A. Ag. 
The disk of an actinal pedicel. 
The basal part of one of its lamine. 
Part of a typical spicule. 
A deformed spicule. 
Sur eh 
Fragment of a deformed spicule. 
6-10. Colobocentrotus Mertensii Brandt. 
Fragment of a spicule. 
1 
Basal part of a lamina. 
Shows the quadratic arrangement of the spicules. 
se 
Typically formed spicule. 
10. Top of a pedicel, taken from the abactinal side and hidden by the large radioles. 
Figures 1-5 are from a specimen, 88 mm. in diameter including the spines and those 
of 6-10 from an individual, measuring 70 mm. in diameter. 
Bonin Ids., Captains Ringgold and Rodgers, N. P. Ex. Ex., Dr. Wm. Stimpson Coll. 
