98 



STOMOBRACIIIUM. 



than to find specimens having twenty or twentj-two chjTniferous tubes, 

 instead of the normal nuniljer. The same is the case m the order of 

 development of the chymiferous tnbes of Zygodactyla, and the other 

 iEquoridjB which I have had occasion to observe. The tnbes are fre- 

 qnently added all on one side of the spherosome, and will be nearly 

 fully formed befoi'e they begin to be developed in the other half The 

 specimens observed of this species are evidently not full-grown, as the 

 ovaries were but imperfectly developed. 

 Key West, Florida (L. Agassiz). 



STOMOBRACHIUM Br.vkdt. 



StnnwhrnclniitH Br. (non Forbes). Prod. ; in Mem. Acad. St. Pctersb., p. 220. 

 Stomohrarlibiin Less. Zooph. Acal., p. 315. 1843. 

 Slomobrachium Agass. Cont. Nat. Ilist. U. S., IV. p. 361. 1862. 



1835. 



Stomobrachiura tentaculatum Agass. 



Slomohracldum tentaculatum Ag.\ss. Cont. Nat. Hist. U. S., IV. p. 361. 1862. 

 Stomohrarhium lenticnhire GoULD {non Br.). Rep. Inv. Mass., p. 349. 1841. 

 f Medusa bimorpha F.\B. Fauna Gronlandiea, No. 356. 1781. 



This species is occasionally found at Nahant during July. It has 

 twelve chymiferous tubes, a small digestive cavity, the folds of the acti- 

 nostome hanging down in four lobes, placed at right angles to one 

 another; these lobes are triangular (Fig. 140), the apex of the triangle 



being placed nearer the origin of the ch>miiferous tubes ; the edges 

 are frilled ; the trend of the triangles is in the direction of four of 

 the chymiferous tubes. Between each two of the chymiferous tubes 

 (Fig. 141) there are from thirty to forty tentacles, in all stages of 



Yv^. MO. Tlic aotinnstonie of Stomobrachiiim tontaculatuni, mafrnififil to show the peculiar 

 mode of carrying llie fohls of the digestive cavity. 



Fig. 141. Stomobraehiuiu tentaculatum, seen from the abactiual pole ; natural size. 



