136 



STAUROPHORA. 



STAUROPHORA Bkindt. 



Staurophora Braxdt (non Forbes) ; in Mem. Acad. St. Petersburg, II. p. 399. 1835. 

 Stauropkora Agass. ; in Mem. Am. Acad., IV. p. 300. 

 Staurophora Agass. Cont. Nat. Hist. U. S., IV. p. 351. 1862. 

 Staurophora Less. Zooph. Acal., p. 297. 1843. 



Fig. 215' 



Staurophora laciniata Agass. 



Staurophora laciniata Agass. ; in Mem. Am. Acad., IV. p. 300, PI. 7. 1849. 

 Staurophora laciniata Agass. Cont. Nat. Hist. U. S., IV. p. 351. 1862. 

 Staurophora laciniata A. Agass. ; in Proc. Boston Soc. Nat. Hist., IX. Figs. 1, 2, 3. 

 Staurophora laciniata Stimps. Mar. Inv. Grand Manan, p. 11. 1853. 



The youngest Medusa of Staurophora which has been observed 

 (Fig. 215^) resembles to such an extent the young MeUcertum (Figs. 



203, 205), as readily to have been taken for dif- 

 ferent stages of the same Jelly-fish, did not the 

 absence of pigment eye-specks enable me to dis- 

 tinguish them sufficiently easily. The develop- 

 ment of the tentacles of the young Medusa ex- 

 plains itself from the accompanying figures (Figs. 216^, 217), as well 

 as the changes of form of the digestive cavity, as it passes from a simple 

 pendent pouch (Fig. 215^) through the different stages (a, h, c, Fig. 

 218), where the digestive cavity loses little by little its individuality, 

 the corners gradually extend along the chymiferous tubes, and in 



Fig. 217 



Fig. 216» 



Fig. 218. 



quite young specimens (c. Fig. 218) the actinostome can no longer be 

 distinguished among the innumerable small folds of the genital pouches. 

 In Fig. 219 the young Staurophora has all the characters of the adult, 

 excepting the size of the different parts. The violet pigment-spots at 

 the base of the tentacles are quite apparent, being perceptible in 



Fig. 215*. Young Staurophora, with eight tentacles. 



Fig. 216*. Quarter of the disk of a young Staurophora, with sixteen large tentacles. 

 Fig. 217. Young Medusa, somewhat more advanced than Fig. 21G*. 



Fig. 218. Different stages of the actinostome, intermediate between that of Figs. 215* and 219. 

 a, the youngest ; b, the next ; c, the oldest. 



