NARCOMEDUSJE — CUNOCTANTHA, ^EGJNURA. 



467 



project outward into the bell-cavity. The mouth-tube develops before the lappets and ten- 

 tacles. The oldest bud had 8 tentacles, 8 lappets, and 16 sense-organs (2 on each marginal 

 lappet). 



The sperm or ova were not developed in the single specimen studied by Browne, and as he 

 states the medusa is probably in an intermediate stage preceding sexual maturity, during which 

 time it produces medusae asexually. 



Fig. 306.— Cunoctantha fowleri, after Browne, in Trans. Linnean Soc. London. 



Found in the Bay of Biscay between 50 fathoms and the surface. 



It is the only Cunoctantha or Cunina known to produce medusa-buds as external out- 

 growths of its body-wall. 



Cunoctantha tenella Bigelow. 



Cunoctantha tenella, Bigelow, H. B., 1909, Mem. Museum Comp. Zool. at Harvard College, vol. 37, p. 54, plates 15-17. 



Bell 7 mm. and more in diameter, higher than a hemisphere, exumbrella smooth. Lappet 

 zone narrow but slightly incised in the tentacular radii. Peronial strands very short. 8 tapering 

 tentacles, as long as bell-radius. At least 3 sense-clubs per lappet as in C. octonana but the 

 otoporps are less prominent. Stomach deep and lenticular with a round mouth-opening. 

 8 nearly triangular, pointed, gastric pouches. A well-developed peripheral, peronial canal- 

 system is present, this being the only known form of Cunoctantha known with certainty to 

 have marginal canals. Colorless. Gonads begin to develop when the medusa is 7 mm. wide. 

 Common in Acapulco Harbor, Pacific coast of Mexico. 



Genus ^GINTJRA Haeckel, sens, emend. 



.Egineta (in part), Gegenbaur, 1856, Zeit. fur wissen. Zool., Bd. 8, p. 261. 



Cunoctona (larval (orm)+ Mginura, Haeckel, 1879, Syst. der Medusen, pp. 317, 343. 



Eeinura Hafckel, 1881, Report on Deep-sea Medusa;, Challenger Expedition, Zool., vol. 4, p. 41— Maas, 1904, Result. Camp. 

 Sci. Prince de Monaco, fasc. 28, p. 37, Genre B, p. 34; 1905, Craspedoten Medusen der Siboga Expedition, Monog. 10, 

 pp. 69, 76; i 9 o6,FaunaArctica,Bd. 4 ,Lfg.3,p.497.—BiGELow,H.B., 1909, Mem. Mus. Comp. Zool. at Harvard College, 



vol. 37, p. 78. . . 



Cunoctona + Mginura, Vanhoffen, 1907, Zool. Anzeiger, Bd. 32, pp. 175, 176; Narcomedusen der Valdwta Expedition, pp. 51, 



71, 72. 



The type species is Mginura myosura Haeckel, from the tropical Atlantic. 



GENERIC CHARACTERS. 



iEginidae with 8 principal tentacles and 8 exumbrella furrows with 8 peronial strands 

 in the radii of the tentacles and with 8 principal stomach-pouches in the radii of the 8 tentacles. 



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