MUSEUM OF COMPARATIVE ZOOLOGY. 18' 



No. 8. — The Echini collected on the Hassler Expedition. By 

 Alexander Agassiz. 



(Published by permission of Prof. Peirce, Supt. of the U. S. Coast 



Survey.) 



The following preliminary notice of the Sea-urchins collected by Pro- 

 fessor Agassiz and Mr. Pourtales during the voyage of the Hassler, 

 contains a description of the most interesting of the new species col- 

 lected. 



The most valuable collection was made off the Barbadoes, at a depth 

 of one hundred fathoms : a very fine specimen of Asthenosoma hystrix 

 was dredged at that point, three young specimens of Coclopleurus flori- 

 danus, — the anal plates of two of the specimens of Coclopleurus were 

 preserved, (there are four of them, as in the Arbaciadre,) — and a re- 

 markable Spatangoid ( Paleopneustes cristatus A. Ag.), noticed in one 

 of the letters of Professor Agassiz to Professor Peirce ; this proves 

 to be another of these remarkable cretaceous types already noticed in 

 the Report of the Echini of the Straits of Florida. A very good series 

 of specimens of Ilemiaster Philippii and of Echinus margaritaceus were 

 collected on the east coast of Patagonia. In the Straits of Magellan 

 the common species are Arbacia Dufresnii and Echinus Magellanicus ; 

 Schizaster Philippii was also found. No Goniocidaris was collected. 

 Along the west coast of South America no novelties were found, and 

 nothing of special importance was brought home except a very fine 

 specimen of Astropyga pulvinata collected at Panama by Lieutenant 

 Cutts. During the stay at the Galapagos a few species of Echini 

 were collected, which leave no doubt that the Galapagos form a part 

 of the Panamic District. The following species were collected there : 

 Cidaris Thouarsii, Strongylocentrotus gibbosus, Toxopneustes semi- 

 tuberculatus, Encope micropora, Ilhynehopygus pacificus. None of the 

 East Indian types often credited to those islands were found at the 

 Galapagos, namely, no Amblypneustes nor Temnopleurus. But we 

 must be careful not to judge from negative evidence, as, notwithstanding 

 the Hassler visited so many parts of the west coast of South America, 



