60 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



ZYGODACTYLA, Brandt, 1835. 

 Zygodactyla cubana, nov. sp. 



Figs. 84, 85, Plate 25. 



Specific Characters. — Young medusa. The bell was quite flat and disk- 

 shaped and 4.5 mm. in diameter. There were 8 long tentacles, 8 rudimentary, 

 undeveloped tentacles, and 16 very small undeveloped tentacle bulbs, that 

 probably develop later into tentacles. The tentacle bulbs possessed excretion 

 papillae and were further distinguished by the fact that there were two ento- 

 dermal green pigment spots one on either side of the bulb (see Figure 85). 

 These spots had the appearance of ocelli, but we do not venture to state that 

 they are such. There were 32 otocysts, each containing one or two spherical 

 otoliths. The velum was well developed. There were 16 radial canals, only 

 8 of which reached the circular vessel. The 8 others projected about half- 

 way from the proboscis to the circular canal. The proboscis was -svide and 

 flask-shaped, and projected for a considerable distance beyond the velar open- 

 ing. The 16 lips were recurved. The gonads were beginning to appear upon 

 the radial canals. The entoderm of the proboscis and radial canals is sage- 

 green. The entoderm of the tentacle bulbs was flesh-colored and the " ocelli " 

 were green. Tortugas, Florida, July 25-29, 1898, and June, 1899. 



Zygodactyla cyanea, Agassiz, L. 



Figs. 23, 23», PI. 11 ; Figs. 33, 34, PI. 15. 



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

 Mesonema cyaneum, Haeckel, E., 1879, Syst. der Medusen, p. 227. 



Specific Characters. — Adult medusa. None of our figures were drawn from 

 full-grown medusae. The bell is flatter than a hemisphere and is about 45 mm. 

 in diameter (22 mm. in Figure 33). The gelatinous substance of the central 

 part of the bell is very thick and there is a well-developed peduncle which 

 projects downward into the cavity of the stomach. The peripheral zone of the 

 bell is quite thin and flexible. There are 90-100 well-developed tentacles with 

 large conical ba.sal bulbs. Each tentacle bulb is hollow and is provided with 

 a conical excretion papilla which projects outward (centrifugally). See Figure 

 34, Plate 15. There are one or two (usually one) otocysts between each suc- 

 cessive pair of tentacles. Each otocyst contains one or two spherical otoliths. 

 The velum Is well developed. There are 90-100 simple, straight radial tubes. 

 The radial tubes do not extend down the peduncle of the proboscis, but empty 

 into the stomach cavity at their highest point. The proboscis is wide and shal- 

 low, and does not protrude beyond the velar opening. The mouth is sur- 

 rounded by numerous crenulated lips which are equal in number to the radial 



