RHEGMATODES FLORIDANUS. 97 



cles between the chymiferous tiil)os, except one hw^o tentacle in the 

 middle of the space ; there is alwa^'s one marginal capsule between the 

 adjoining tentacles. These Medusie are slow in their movements, allow- 

 ing themselves to be carried along with the current, after one or two pul- 

 sations ; they swim near the surface. Found at Naushon in September. 



Buzzard's Bay, Naushon (A. Agassiz). 



Cat. No. 278, Naushon, Septembei", 18G1, A. Agassiz. Medusa. 



Rhegmatodes floridanus Agass. 



RJicgmaloih's floridanus Agass. Cont. Nat. Hist. U. S., IV. p. 3G1. 18G2. 



A second species of this genus (Fig. 139) is found along the Floi'ida 

 Reefs. It resembles the young of the northern species at the time 

 when it has from sixteen to twenty-four chymiferous tubes ; the part of 

 the gelatinous disk which projects into the interior cavity of the bell is 

 larger, giving the sjiherosome a somewhat heavy look ; the fringes of 

 the actinostome are longer ; the ovaries are confined to a small part of 

 the chymiferous tubes, and do 

 not begin at the point of junc- 

 tion of their upper extremity, 

 but a short distance from it ; the 

 circular tube is large ; in speci- 

 mens having sixteen chymiferous 

 tubes, there were forty marginal 

 tentacles ; in specimens having 

 twenty, there were sixty. This 

 species is much smaller than its 

 northern representative, speci- 

 mens having already sixteen chy- 

 miferous tubes not being more 

 than an inch in diameter ; while 

 specimens of the northern species, which have attained the same de- 

 velopment, measure about two inches. The marginal capsules contain 

 two to three granules each. 



Additional chymiferous tubes in the yEquoridae are developed from 

 the digestive cavity, as has already been shown by Kolliker, and 

 not from the vertical tube, as is the case in the branching tubes of 

 Willia. They are at first simple short sacs, which gradually extend in 

 length till they become long tubes, ojiening into the circular tul>e ; the 

 chymiferous tubes and the marginal tentacles are not developed with 

 equal regularity, m the order of their cycles ; the chymiferous tubes 

 especially are very irregularly formed, and nothing is more connnon 



Fig. 139. Rhegmatodes lloridaims, natural size. 

 NO. 11. 13 



