Verrill, Xotes on Radiata. 377 



No. 6. — Review of the Corals and Polyps of the West Coast of 

 America. By A. E. Veruill. 



Presented, April, 1868. 



Recent explorations of the west tropical coast of America, prin- 

 cipally by Mr. F. H. Bradley for the Museum of Yale College, have 

 contributed so much to the knowledge of the Polypi of that region 

 .and have so increased our store of specimens, that a new and much 

 more complete catalogue of the species lias become indispensable for 

 a proper imderstanding of the geographical distribution of the ani- 

 mals of this class. The Smithsonian Institution lias contributed the 

 species collected by John Xantus, Esq., at Cape St. Lucas. 



In a paper published two years ago,* the writer enumerated nearly 

 all the species then known from Panama and called attention to the 

 remarkable contrast between the polyp-fauna? of the Atlantic and 

 Pacific coasts of Central Amei'ica, and the bearing of these facts upon 

 the supposed former connection between the two oceans, across the 

 Isthmus of Panama. 



The additional forms now presented make these contrasts still 

 greater and more remarkable, and add greater force to the evidence 

 then brought forward to show that no deep or extensive water con- 

 nection, sufiicient to modify the ocean curi'ents, can have taken place 

 since the existence of the species now living upon each coast. 



The Panamian fauna pi'oves to be remarkably rich in Gorgonaeea, 

 no less than 43 species having already been obtained. The genus 

 Muricea appears to attain here its greatest development, since 15 spe- 

 cies, besides several peculiar varieties, perhaps distinct, are in our col- 

 lection from Panama Bay, and others from Acapulco and Peru, Avhile 

 from the West Indies there are but four well-ascertained species. The 

 occurrence of two peculiar, gigantic species of Pavonia, a genus of 

 corals hitherto known only in the Indo-Pacific faunae, is notcAvorthy, 

 and also the presence of a peculiar new form of Dendrophyllia. 



The classification here followed is that proposed by the writer three 

 years agof with a few changes that have become necessary by a better 

 knowledge of the anatomy of some groups and the discovery of new 

 forms. 



* Proceedings of the Boston Society of Natural History, vol. x, p. 323, 1865. 

 f Proceedings of the Essex Institute, vol. iv, p. 145, 1865. See also Memoirs of the 

 Boston Society of Natural History, vol. i, 1864. 



