No. 7. — Explorations of the Surface Fauna of the Gulf Stream, 

 under the Auspices of the U. S. Coast Survey, hy Alexander 

 Agassiz. 



(Published by permission of Carlile P. Patterson and J. E. Hilgard, Supts. of 

 the U. S. Coast Survey.) 



Notes on Acalephs from the Tortugas, xvith a Description of New Genera 

 and Species. By J. Walter Fewkes. 



The following pages contain descriptions of new raednScC collected at 

 Key West and the Tortugas Islands, in March and April, 1881.* They 

 contain an account of the anatomy and development of Linerges, Cas- 

 siopea (Polf/clonia), Ocyroe, and a stage in the embryology of Eticharis. 

 Six new species of Siphonophora, two new genera and three new species 

 of Hydroida, are also described. New larval stages of growth, illustra- 

 tive of the development of Glossocodon, are also figured and described. 



CTENOPHORA. 

 Beroe ovata, Esch. 



Plate IV. Fig. 1. 



B. ovata is common along the Florida Keys. It has a quicker motion and is 

 larger than B. roseola. The sense area is also more prominent. 



Eucharis multicornis,. Esch. 



Plate VII. Figs. 11, 12. 



A larva of Eucharis, closely resembling the young of E. midticornis, was 

 found at Key West. It is smaller than the adults of E. multicornis,f and is 



* An account of A. Agassiz's explorations of the Tortugas, when these medusee were 

 found, is published in Harv. Univ. Bull., XIX. p. 218, and Bull. Mus. Comp. Zobl., 

 IX. 3. I am indebted to A. Agassiz for affording an opportunity to visit Key West 

 and the Tortugas as his assistant. 



t Chun, Die Ctenophoren der Golfes von Neapel, &c., p. 297. 

 VOL IX. — NO. 7. 



