108 CREMATOSTOMA. 



carried curled tightly to the edge of the disk. Found in great num- 

 bers, from February to May, along the Florida Reef 



Florida, Key West (L. Agassiz). 



Cat. No. 349, Florida, L. Agassiz. Medusa. 



Cat. No. 350, Tortugas, Fla., May, 1858, L. Agassiz. Medusa. 



Zygodactyla coerulescens BR. 



Zygodactyla coerulescens BR. ; in Mem. Acad. St. Petersb., p. 360, PI. 5. 1838. 

 Zygodactyla coerulescens AGASS. Cont. Nat. Hist. U. S., IV. p. 360. 1862. 

 Mesonema coerulescens BR. ; in Mem. Acad. St. Petersb., p. 360. 1838. 

 Mesonema ccerulescens LESS. Zooph. Acal., p. 307. 1843. 



Entrance of Straits of Fuca (A. Agassiz). 



CREMATOSTOMA A. AGASS. 



Crematostoma A. AGASS. ; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 360. 1862. 



The genera of ^Equoridse found on the Pacific coast are either 

 identical with those of our coast, or have representatives which give 

 to the members of that family found on the two sides of the continent 

 a striking similarity. Stomobrachium, Zygodactyla, and ^Equorea are 

 found both in the Atlantic and Pacific ; we have Rhegmatodes, which 

 has as yet no representative on the Pacific coast of North America, 

 while Crematostoma has not been found on the Atlantic side. 



This genus recalls Zygodactyla, in having a large digestive cavity ; it 

 is, however, much less contractile than in that genus, and hangs always 

 far below the level of the circular tube. The actinostome, as in Zygo- 

 dactyla, is surrounded by a number of narrow, lanceolate, fimbriated 

 lips, one for each chymiferous tube, which are from sixty to eighty in 

 number. 



Crematostoma flava A. AGASS. 



Crematostoma flava A. AGASS.; in Agassiz's Cont. Nat. Hist. U. S., IV. p. 360. 1862. 



The lower part of the digestive cavity, immediately above the acti- 

 nostome, is alone capable of considerable contraction, the digestive 

 cavity hanging down like a large cylindrical sac, with numerous longi- 

 tudinal folds extending from the origin of the chymiferous tubes along 

 the whole length of the sac to the actinostome. The chymiferous 

 tubes are broad, extending a short distance along the projection of the 

 spherosome into the cavity of the bell. The ovaries extend the whole 



