MUSEUM OF COMPARATIVE ZOOLOGY. 147 



the surface fauna of the Gulf Stream. From the existence there of cer- 

 tain species of corals, these islands may prove, on trial, the best fitted 

 for a prolonged study, not only of corals, but also of the Atlantic sur- 

 face fauna. 



In spite of the unfavoi'able weather, enough was accomplished to show 

 conclusively that by far the greater number of the pelagic animals known 

 from the Atlantic coast of the United States are inhabitants of the sur- 

 face of the Gulf Stream, and are driven on the northern shores by 

 the prevailing southwesterly winds during the summer and autumn 

 months. 



An enumeration of the pelagic species observed during our stay at 

 Key West and at the Tortugas would carry me too far. I will only 

 mention in a general way the presence of a couple of species of Firoloidea, 

 of Phyllirhoe, of several Appendicularise, of a small Pyrosoma, of a Dolio- 

 lium, two species of Salpa, one of which is our common Northern form, 

 and of half a dozen species of Pteropods. Three or four of these, as well 

 as a large proportion of the other pelagic animals, find their way north 

 as far as Newport. In fact, much of our surface work during March and 

 April reminded me of similar work done at Newport from the end of 

 July until late in September, but of course the number of specimens 

 was far greater at the Tortugas. The surface fauna of the Gulf Stream 

 nan undoubtedly be best studied at the Tortugas, though important ad- 

 ditions to our knowledge of it have been made at Charleston, and at 

 Beaufort, N. C., and along the coast of New Jersey, of Rhode Island, 

 and of Southern Massachusetts. 



It is remarkable that Janthina, which is so common at the Tortugas, 

 should not find its way farther north than off Cape Hatteras, in common 

 with other surface things, where I have frequently seen it while on the 

 " Blake," and on other occasions. 



There are also found at the Tortugas a large number of pelagic Crus- 

 tacea in their embryonic stages, among them Phyllosoma and the Nau- 

 plius stage of a Peneus similar to that observed by Fritz Miiller ; also 

 multitudes of young Annelids, Mollusks, Actiniae, the planulte of several 

 of the Corals, Echinoderm embryos, and a host of young pelagic Fishes, 

 among which I may mention the young of the Flying-fish and Leptoceph- 

 ali. For the study of the young stages of Fishes and of Acalephs the 

 Florida reefs present an unrivalled field of observation. We were greatly 

 disappointed in the number of the pelagic Foraminifera. We did not 

 meet once a species of Globigerina, which was found quite commonly off 

 the Tortugas in my former cruises in the " Blake," and which Mr. Pour- 



