TUBULARI^. 149 



Suborder TUBULAHI^ Agass. 



TubularicE Agass. Cont. Nat. Hist. U. S., IV. p. 338. 1862. 

 Tubularina Ehrenb. Corall. d. Rothen jMeeres. 

 Tuhularina and Hydr'ma Johnst. Brit. Zooph., p. 29. 



Family NEMOPSIDiE Agass. 



Nemopsidce Agass. Cont. Nat. Hist. U. S., IV. p. 345. 1862. 



NEMOPSIS Agass. 



Nemopsis Agass. ; in Mem. Am. Acad., IV. p. 289. 1849. 



Nemopsis McCr. Gymn. Cliarl. Harbor, p. 57. 



Nemopsis Agass. Cont. Nat. Hist. U. S., IV. p. 345. 1862. 



Nemopsis Bachei Agass. 



Nemopsis Bachei Agass. ; in Mem. Am. Acad., IV. p. 289, Fig. 1849, • 

 Nevwpsis Bachei Agass. Cont. Nat. Hist. U. S., IV. p. 345. 1862. 

 Nemopsis Gihbesi McCr. Gj-mn. Charl. Harb., p. 58, PI. 10, Figs. 1- 7. 

 Nemopsis Bachei A. Agass. ; in Proc. Bost. Soc. Nat. Hist., IX. p. 98, Figs. 26, 27. 



Owing to the great changes through which Nemopsis passes before 

 it reaches its adult form (comj)are Figs. 227-230), it is impossible 

 to decide at present, before having seen the Nemopsis Qibbesi of 

 McCrady, found at Charleston, whether he has not described again, 

 under a new name, the iV. Bachei found by Professor Agassiz m Vine- 

 yard Sound in 1848, and of which a wood-cut was published in the 

 Memoirs of the American Academy for 1849. The circumstances under 

 which the drawing was made precluded the possibility of great accu- 

 racy ; it was a simple sketch ; and as this Medusa has not been ob- 

 served since, until the publication of McCrady's paper on the Medusae 

 of Charleston Harbor, it is not astonishing that he should have described 

 it as a new species, having only for his guide that single wood-cut. 



I have had, during the summer of 1861, the opportunity Fig. 227. 



of observing this Medusa, at the time when it had only 

 four tentacles to each marginal bulb (Fig. 227), no ova- 

 . ries, and was not more than a sixteenth of an inch in diam- 

 eter. The shape of the bell, and of the oral tentacles, the 

 mode of branching of the digestive cavity and of the tentacles, agree 

 so well with the drawings and descriptions of McCrady of similar stages 

 in iV". Gibbesi, that I am inclined to consider them as identical. The 



Fig. 227. Youngest Nemopsis observed, having four tentacles at the base of each chymiferous 

 tube. 



