TUBULAROE. 149 



SUBORDER TUBULARI^E AGASS. 



Tubularity AGASS. Cont. Nat. Hist. U. S., IV. p. 338. 1862. 

 Tubularlnn EHHENB. Corall. d. Rothen Meeres. 

 Tubularina and Ilydrina JOHXST. Brit. Zooph., p. 29. 



Family NEMOPSID^E 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. Charl. Harbor, p. 57. 



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



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Nemopsis Bachei AGASS. 



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

 ' Nemopsis''Bachei' AGASS. Cont. Nat. Hist. U. S., IV. p. 345. 1862. 

 Nemopsis Gibbesi McCR. Gymn. Charl. Harb., p. 58, PL 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 (compare Figs. 227-230), it is impossible 

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

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

 under a new name, the N. Bachei found by Professor Agassiz in 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 Medusas 

 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 N. 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. 



