74 



EUCHEILOTA. 



while Sarsia, Nemopsis, and Margelis are as active when young as 

 when full grown. 



Eastport, Maine (L. Agassiz) ; Massachusetts Bay (A. Agassiz) ; Buz- 

 zard's Bay (A. Agassiz). 



Cat. No. 280, Naushon, A. Agassiz, September, 1861. Medusa. 



Cat. No. 450, Nahant, A. Agassiz, June, 1864. Medusa. 



Fi?. 103. 



Oceania gregaria A. Agass. 



Oceania gregaria A. Agass. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 353. 1862. 



This Medusa is somewhat smaller than its Eastern representative. 

 It diflfers from it strikingly by the great length of the slender lips 



of the actinostome (Fig. 103) ; the color of 



the genital organs and of the sensitive bulb 



of the tentacles is a beautiful pale yellow, 



in strong contrast to the dark coloring of 



our species ; the marginal tentacles are only 



moderately contractile. The whole surface 



of the water for several miles was often thickly covered with these 



Medusas. Found in the Gulf of Georgia, from June to October. 



Gulf of Georgia, W. T. (A. Agassiz). 



Cat. No. 124, Gulf of Georgia, W. T., June, 1859, A. Agassiz. Medusa. 



EUCHEILOTA McCr. 



Eiicheilofa McCr. Gymn. Charl. Harb., p. 84. 

 Eucheilota Agass. Cont. Nat. Hist. U. S., IV. p. 353. 



1862. 



Eucheilota ventricularis McCr. 



Eucheilota ventricularis McCr. Gymn. Charl. Harbor, p. 85, PI. 11, Figs. 1 -3 ; PI. 1, Figs. 1, 2. 

 Eucheilota ventricularis Agass. Cont. Nat. Hist. U. S., IV. p. 353. 1862. 

 Eucheilota ventricularis A. Agass. Proc. Bost. Soc. Nat. Hist., IX. Figs. 16, 17. 



Fifr. 104. 



The small Medusa represented in Fig. 104 is exceedingly 

 common at Naushon, and I suppose it to be a young of this 

 species, though I did not trace its development long enough 

 to satisfy myself fully on this point. It has the characters 

 of the genus as given by McCrady, with the exception of 

 the ovaries, which were not yet developed in the oldest 

 specimens observed. Young specimens, of a sixteenth of an 

 inch in diameter, have four tentacles, one opposite each of 

 the chymiferous tubes, of the length of the diameter of the 



Fig. 103. One of the four lips of tlie actinostome of Oceania gregaria. 

 Fig. 104. Young of Eucheilota ventricularis McCr. 



