PROCEEDINOS 



OF THE 



WASHINGTON ACADEMY OF SCIENCES 



Vol-. IV, pp. 521-531. September 30, 1902. 



PAPERS FROM THE HOPKINS STANFORD GALA- 

 PAGOS EXPEDITION, 1898-1899. 



XII. 



ECHINODERMATA. 



By Hubert Lyman Clark. 



Professor of Biology, Olivet College, Michigan. 



CONTENTS. 



Introduction , 521 



Asteroidea 522 



Ophiuroidea 524 



Echinoidea 526 



Holothurioidea 527 



Comparison of Galapagos and Bermuda Echinoderms 528 



The Holothurians of Clipperton Island 530 



INTRODUCTION. 



Although the collection of Galapagos echinoderms made by 

 the Hopkins Stanford Expedition is small, and contains no new 

 species, it nevertheless adds something to our knowledge of the 

 marine fauna of those islands. Most of the specimens were 

 collected in shallow water at Tagus Cove, on the west side of 

 Albemarle Island, or at Iguana Cove, at the southwest end of 

 the same island. A few brittle stars were taken at Narboro. 

 A few species were collected only with the dredge, in Tagus 

 Cove. Previous knowledge of the Galapagos echinoderms has 

 been very scanty, for although a number of collecting expedi- 



Proc. Wash. Acad. Sci., Sept., 1902. 521 



