MAYER: MEDUSA FROM THE TOKTUGAS, FLORIDA. 81 



cystous arise from the side of the feeding-polypite. These are stiff ami 

 slender, and their distal extremities are armed each with several oval nema- 

 tocyst cells of large size. The entoderm of the cystons display large, highly 

 refractive oval cells quite similar to the digestive cells of the feeding-polypite. 

 About half a dozen branched tentacles arise from between the cystous. Each 

 branch terminates in a complexly formed coiled nematocyst battery which is 

 enclosed within the substance of the terminal knob. The knob ends distally 

 in a bladder-shaped ampulla and a pair of long curved finger-shaped processes, 

 the latter being lined on their convex sides with a row of hair-cells (see Figure 

 120). Several small hernia-like protuberances, which probably consist of 

 young swimming-bells, arise from the side of the main axis immediately below 

 the level of the float. The bracts are three-cornered, and their sharp distal ends 

 are armed with large nematocyst cells. The free edges of the primitive larval 

 bract are lined with a row of small nematocyst cells. Each bract is provided 

 with a long slender, unbranched canal. The pigment cells of the float are rich 

 brown in color. The entoderm of the feeding-polypite and cystons is of a de- 

 cided pink, and the coiled nematocyst batteries in the tentacle knobs are of a 

 more decided reddish color. The entoderm of the float and the ectoderm of 

 the terminal knobs of the tentacles are yellow, and the canals of the bracts are 

 grass-green in color. 



IV. CTENOPHOKyE. 



OCYROB, Rang, 1826. 

 Ocyroe erystallina, Kang. 



Fig. 105, Plate 31. 



Ocyroe erystallina, Rang, S., 1828, Mem. Soc. Nat. Paris, Tom. IV. p. 172, PI. XX. 

 Fig. 4. 



This Ctenophore is quite often met with at the Tortugas, Florida, from 

 April until July. It makes its appearance at the surface when the ocean is 

 perfectly flat and calm, and even a slight ripple is sufficient to induce it to 

 sink into the depths. The species appears to be widely distributed over the 

 Tropical Atlantic. 



BOLINA, Mertens, 1833. 

 Bolina vitrea, L. Agassiz. 



Figs. 91, 92, Plate 27. 



Bolina vitrea, Agassiz, L., 1860, Cont. Nat. Hist. U. S., Vol. III. pp. 269, 289, 



Fig. 93. 

 Bolina littoralis? McCrady, J., 1858, Proc. Elliott Soc, Charleston, p. 1, PI. 14. 



