NARCOMEDUSjE — CUNANTHA, ^GINA. 



449 



medusa (C. striata) may possibly be mature ( ?) and may be considered as the type of the genus. 

 It is probable, however, that C. striata is only a young Mgina, and the "jenus "^Cunantha 

 is, I believe, only a developmental stage of Mgina. No medusa of this "genus" has been 

 described since Haeckel's account in 1879. 



GENERIC CHARACTERS. 



jEginidae with 4 tentacles inserted at the distal ends of 4 simple, uncleft, peripheral diver- 

 ticula of the central stomach. 



Cunantha primigema Haeckel, 1879 (p. 314, taf. 19, fig. I), and Cunantha petasoides, ibid., 

 p. 315, are larval forms of Mgina, the species being undetermined. Further information con- 

 cerning them should be sought for in Haeckel's System der Medusen. 



The type species is Cunantha striata Haeckel, first described by Metschnikoff, 1870, 

 under the name Cunina striata. It is found in the Mediterranean. 



The gonads of many Narcomedusae begin to develop long before the medusa has assumed 

 the features of the mature stage, and this fact has caused considerable confusion in classifica- 

 tion, immature stages being described as mature. It is highly probable that both Cunantha 

 and 'dinar x ha of Haeckel are only successive developmental stages of Mgina. 



Cunantha striata Haeckel. 



Cunina striata, Metschnikoff, E., 1870, Gesell. Freunde Naturwissen. Moskau, tome 8, p. 362, plate 6, figs. 4-8. 

 Cunantha striata, Haeckel, 1879, Syst. der Medusen, p. 315. 



Bell 12 mm. wide, 8 mm. high, hat-shaped. Margin with 4 wide, almost quadratic lap- 

 pets as long as the radius of the central biconvex, lenticular part of the bell. 4 rudimentary 

 tentacles, hardly as long as half the bell-radius, arise a short distance above the margin. 24 

 sensory-clubs, 6 on each lappet, have each 3 to 4 concretions of entodermal origin. Very long 

 conspicuous, exumbrella sensory tracts, or otoporpae, above the marginal sense-clubs extend 

 about half-way up the sides of the exumbrella. The exumbrella bears converging radial rows 

 of nettling cell's, extending from the margin nearly to the apex. Mouth simple, without oesoph- 

 agus tube. The 4 radial peripheral stomach-pouches are very small and resemble ordinary 

 radial-canals. The peronial strands are also very short, and thus the tentacles arise at a very 

 short distance above the margin. The gonad forms a simple ring in the lower wall of the 

 stomach-margin. 



Found by Haeckel at Villafranca, Mediterranean, in April, 1864. It has not been seen 

 since this time. It is probably only a young Mgina. 



Genus jEGINA Eschscholtz, 1829. 



Vp.na Eschscholtz, 1829, Syst. der Acalephen, p. 113.-MAAS, 1893, Ergeb. der Plankton Expedition, Bd. 2, K. c., p. 53; 

 ' ; 9 o™ult.Can ip .Sci y Prince de Monaco', fasc 28, p. ,J, genre A, p. 33; -9°4, Bull du Musee Oceanograph Monaco, 

 N V , Craspedoten Medusen der Siboga Expedition, Monog. 10, pp. 69, 70; 1906, Fauna Arcfca, Bd. 4, 



Lfg. 3, pp' 485, 497, Jena.-Vanhoffen, 1908, Narcomedusen Valdivia Expedition, p. 4 7.-Bigelow, H. B., 1909, Mem. 

 Museum Comp. Zool., vol. 37, p. 72. 

 (>)C.anipane!la,AGASSlz, A., 1865, North American Acal., p. 52. „,.._.,, 



Cunantha (in part)+ Cunarcha, young medusa^ Mgma+ Solmundu*, Haeckel, .879, Syst. der Medusen pp. 314, 3>5, 337, 35>- 

 Cunarcha (young medusa), Haeckel, 1881, Report Deep Sea Medusae, Challenger Expedit.on, Zool., vol. 4, p. 24. 

 Solmundus+ Mgina, Vanhoffen, 1907, Zool. Anzeiger, Bd. 32, p. 175. 



The type species is Mgina citrea Eschscholtz, from the Pacific, 34 N., 201° W. from 

 Greenwich. 



GENERIC CHARACTERS. 



^Eginidae with 4 to 6 tentacles and 4 to 6 peronial strands. When mature there are 8 to 12 

 peripheral stomach-pouches which may display cleft margins. The gonads develop in the 

 subumbrella ectoderm of these stomach-pouches. Marginal loop-canals; otoporpae; second- 

 ary, marginal tentacles; peronial furrows; or cruciform lips may or may not be present. 



The genus Cunarcha and also Cunoctantha primigema Haeckel are specimens of Mgina 

 with 4 tentacles and 4 bifurcated peripheral stomach-pouches in the tentacular radii. A later 

 stage is seen when the 8 ends of these 4 bifurcated stomach-pouches become so large that the 



