TUBULARIADCE. 189 



Cat. No. 21, Suisconset, Mass., July, 1849, L. Agassiz. Hydromedu- 

 sarium. 



Cat. No. 22, NaiTshon, Sept, 1861, A. Agassiz. Hydromedusarium. 



Cat. No. 23, Newport, R. L, Prof. J. Leidy. Hydromedusarium. 



Cat. No. 24, Newport, R. L, S. Powell. Hydromedusarium. 



Cat. No. 25, Beverly, Mass., T. Lyman. Hydrarium. 



Cat. No. 26, West Yarmouth, Mass., Aug. 1860, T. Lyman. Hydrarium. 



Cat. No. 407, Nahant, September, 1862, A. Agassiz. Hydrarium. 



Family TUBULARIAD^E Johnst. 



Tubulariadce JOHXST. (restr. Agass.) ; in Trans. Berwick Club, p. 107. 

 Tubulariadce AGASS. Cout. Nat. Hist. U. S., IV. p. 342. 1862. 



EUPHYSA FORBES. 



Euphysa FORBES. British Naked-eyed Medusae, p. 71. 1848. 

 Euphysa AGASS. Cont. Nat. Hist. U. S., IV. p. 343. 1862. 



The outline of the bell of this genus is entirely different from that 

 of Corymorpha or of Hybocodon. It can at once be recognized by its 

 quadrangular shape, and the great thickness of the spherosome above 

 the base of the digestive cavity, which is short and cylindrical. The 

 tentacles also are always short and hollow, but are developed in the 

 same proportion as in Corymorpha, one stout triangular one, a pair 

 somewhat less advanced, and an odd rudimentary one ; the large tenta- 

 cle never attains the size which it does in Hybocodon or in Corymorpha. 

 The pigment bands at the base of the tentacles are quite short, and 

 extend but little way along the chymiferous tubes. The ovaries are 

 placed on the sides of the proboscis ; the bell is symmetrical. 



Euphysa virgulata A. AGASS. 



This Medusa attains a size of about half an inch ; the polar diameter 

 is nearly one third greater than the actinal (Fig. 316) ; the proboscis 

 (Fig. 317) is short, not more than half the length of the inner bell (Fig. 

 316) ; the veil is slightly indented (Fig. 318) ; the tentacles (t, t', 

 Fig. 318) are triangular, and covered with large granules of a milky 

 color, with a band of intensely pink pigment-cells extending a short 

 distance (p. Fig. 319) along the chymiferous tubes, from the base of 

 the tentacles ; the proboscis is cylindrical, of a light yellow color, with 

 a perfectly smooth actinostome, and fatty globules generally accumu- 

 lated at the base (<?, Fig. 317), as in Corymorpha and Hybocodon. 



