BAHAMA MEDUSA. 17 



65, Plate VII). It is interesting to see that even before it is set free the 

 gonads of the budding medusa are well developed (b., Fig. 65). 



Phortis pyramidalis. 



Fig. 25, Plate III. 



Eutima pyramidalis, Aoassiz, L., 1862; Cont. Nat. Hist. U. 8., Vol. IV., p. 363. 



Agassiz, a., 1865 ; North Amer. Acal., p. 118. 



Habckeii, E., 1879; Das Syst. der Medusen, p. 191. 

 Phortis pyramidalis, Mateb, A. G., 1900; Bull. Mus. Comp. Zool. at Harvard Coll., Vol. 

 XXXVII., p. 59, Figs. 21, 21a, Plate 10. 



Mature Medusa: Bell about 35 mm. in diameter. Slightly flatter than a 

 hemisphere. The gelatinous substance is thick and rigid, and the manu- 

 brium is situated at the extremity of a wide, conical i)eduncle, which fills 

 the greater portion of the bell-cavity. About 100 short tentacles alternat- 

 ing with 100 otocysts each containing a single otolith. No lateral cirri. 

 Four narrow straight radial canals. Four gonads upon the radial canals 

 near the circular vessel. Manubrium small and urn-shaped with four 

 prominent recurved lips. Manubrium, gonads, and tentacle-bulbs delicate 

 turquoise, other parts transparent. Common at Bahamas and Tortugas. 

 Brilliantly phosphorescent at night, giving an intense blue-green light. 



Zygodactyla cyanea, L. Agassiz. 



Figs. 26, 27, Plate III. 



Agassiz, L., 1862; Cont. Nat. Hist. U. S., Vol. IV., p. 361. 

 Agassiz, A., 1865; North Amer. Acal , p. 107, Fig. 159. 



Mayer. A. G., 1900; Bull. Mus. Comp. Zool. at Harvard Coll., Vol. XXXVII, p. 60. Figs. 23, 

 23a, PI. 11, Figs. 83, 34, PI. 15. 



Bell about 45 mm. in diameter, flatter than a hemisphere. Gelatinous 

 substance of the central part of the bell thick with a well developed pedun- 

 cle, which projects downward into the cavity of the stomach. Peripheral 

 zone of the bell thin and flexible. About 100 long tentacles and 100 simple 

 straight radial canals upon which the linear gonads are situated. Each 

 tentacle-bulb hollow and conical, and provided with a conical excretion 

 papilla which projects outward from the exumbrella side of the bell. In 

 addition to the well developed tentacles there are about 300 small rudimen- 

 tary tentacle-bulbs, each provided with an excretion papilla, and also about 

 300 otocysts each containing two otoliths. The manubrium is wide and 

 shallow and does not project beyond the velar opening. There are as many 



