MUSEUM OF COMPARATIVE ZOOLOGY. 139 



V. Notice of a few SiphonophorsD and Velellidse from the East- 

 ern Coast of the United States. 



Up to the present time few forms of either of these groups of Jelly- 

 fishes have been described from the waters of our bays and sounds. 

 They seem to be only occasional visitors, blown into the neighborhood 

 of our shores from mid-ocean, or brought there from the tropics by the 

 Gulf Stream. The wealth of tubular Medusse which one finds in the 

 Mediterranean is unknown on New England coasts or in Charleston 

 Harbor, localities in which these animals have been best studied. Upon 

 many single excursions on the quiet bays near Nice, in Southern France, 

 I have taken eight different genera of Siphonophorse ; but their rarity is 

 so great at Newport that seldom have more than one or two genera 

 been taken by me in the same day ; and a whole summer, in which I was 

 almost daily upon the water, has passed without the observation of a 

 single genus. A similar case of absence of all pelagic animals happened 

 at Villefranche, last November. In that month, although I was on the 

 water dail}^ I observed not only no Sij)honophores, but also none of those 

 Heteropods and Pteropods which later appeared in such numbers. Certain 

 of the Siphonophoree, however, are more abundant with us than in Ville- 

 franche, Naples, or Messina. Physalia caravella is now rarely taken in 

 numbers by naturalists at either of these stations ; but many examples 

 o^ Physalia arethusa may be found almost any summer in Vineyard Sound 

 or the entrances to Narragansett Bay. 



The well-known Physalia arethusa is the most common of New Eng- 

 land Siphonophores. It was long ago described by one of the pioneers 

 in the study of Jelly-fishes, and later beautifully figured by Prof. Agas- 

 siz in the Contributions to the Natural History of the United States. 

 Prof. McCrady* describes a form, Physalia aiirigera, which is consid- 

 ered by Mr. Alex. Agassizf as the same species. In the Catalogue of 

 the North American Acalephse, the list of places from which speci- 

 mens of Physalia arethusa had been taken includes localities all the way 

 from Cape Cod to Florida, and beyond in the West Indies. 



The two floating Hydroids, Velella and Porjnta, so closely allied to the 

 Tubularians and known as the Velellidse, are also found in our waters. 

 The problematical genus Pataria,^ by some supposed to be the young 

 of Velella, in swarms of which it is generally found, and by others an 

 immature Porpita, I think has not been described from our coast. I 



* Gymnopthalmata of Charleston Harbor, 1857. 



+ North American Acalephse, 1865. 



X Pagenstecher, Zeitscli. f. Wiss. Zool., Bd. XIL, 1863. 



