144 ' CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



EXPLANATION OF PLATE 20 



Fig. 1. Clypeaster cubensis Cotteau. Upper surface of test. Cal. Acad. 



121.7 



Sci. No. 370. X 



147 



Fig. 2. Schizaster scherzeri Gabb. Lateral surface of test. Cal. Acad. 

 80 

 Sci. No. 368. X — 



55 



