Jt 



Bulletin of the Museum of Comparative Zoology 

 AT HARVARD COLLEGE. 



Vol. LI. No. 7. 



THE CIDARIDAE. 



By Hubert Lyman Clark. 



The LiV 

 Museum of Comparative Zo 

 -v. harvard University - 



With Eleven Plates. 



The Library 



MuseuE of Comparative Zoology 



Harvard University 



CAMBRIDGE, MASS., U.S.A.: 



PRINTED FOR THE MUSEUM. 



December, 1907. 



