NARCOMEDUS.E — CUN1NA. 



481 



A generation of medusae is produced upon the stomach-wall of the parent medusa, the 

 growing medusae lying within the stomach-cavity. These young medusae have at first 4, then 

 8, and finally about 1 1 to 16 tentacles. They have neither marginal sense-clubs, velum, nor bell 

 collar, but in other respects they resemble the first sexual generation young of C. proboscidea. 

 They give rise asexually to aboral medusa-buds one at a time. According to Stschelkanow- 

 zeff, 1905-06, the eggs of this first sexual (stomach-cavity) generation of C. rubiginosa are 



322. 



321. 



Fig. 321. — Cunina prolijera, after Keferstein and Elders, 1861 (Mgineta gemmifera). 

 Fig. 322. — Cunina prolijera, after Gegenbaur, 1854. Bell-lappets contracted. 

 Fig. 323. — Cunina duplicata, after Maas, in Ergeb. Plankton Expedition. 



set free into the ocean and develop into planula larvae which attach themselves to the lips or 

 gastric cavity of Geryonia. Here they grow into a stolon-like larva, which gives rise asexually 

 to numerous medusa-buds, which on being set free grow into the large, free-swimming 

 medusa we call C. prolijera. 



C. prolijera is quite common in the Mediterranean during the winter, but is more abun- 

 dant in spring. 



Cunina peregrina Bigelow. 



Cunina peregrina, Bigelow, H. B., 1909, Mem. Museum Comp. Zool. at Harvard College, vol. 37, p. 59, plates I, 15, 28, and 54. 



Bell 14 mm. wide, highly arched, gelatinous substance thick, exumbrella smooth, except- 

 ing along the lines of the otoporpae. 8 to 12 stifF tentacles, about as long as bell-radius. A 

 prominent, peronial pad underlies the base of each tentacle. 4 to 8 sensory-clubs on each 

 lappet. Each club contains a single concretion. The otoporpae are narrower than in C. globosa 

 and of nearly uniform width throughout their length. The marginal stomach-pouches are 

 about as broad as long, square in outline, with very narrow clefts between them. There is no 

 peripheral canal-system. The spermatozoa form ridge-like thickenings of the subumbrella 

 gastric wall along the margins of the gastric pockets, but the ova are developed diffusely over 

 the gastric pockets. There are powerful muscles in the subumbrella surface of the lappets. 

 Colorless. Common on surface in eastern tropical Pacific. 



Bigelow found a budding stolon attached to the subumbrella surface of Rhopalonema 

 velatum, which was giving off medusae resembling C. peregrina. 



Cunina mucilaginosa De Blainville. 



Medusa mucilaginosa, de Chamisso et F.ysenhardt, 1821, Nova Acta Acad. Nat. Curios. Leop. Carol., tome 10, part 2, p. 



360, tab. 30, figs. 2, A, B. 

 Cunina mucilaginosa, de Blainville, 1834, Man. d'Actinologie, p. 279. — Haeckel, 1879, Syst. der Medusen, p. 321. 

 Scyphis mucilaginosa, Lesson, 1843, Hist. Zooph. Acal., p. 282. 

 Solmaris mucilaginosa, Vanhoffen, 1908, Narcomedusen der Valdivia Expedition, p. 59. 



See synoptic table of species of Cunina. 



Vanhoffen finds that this medusa is represented among the captures of the Valdivia. 

 Our knowledge of it is still quite imperfect. 



Cunina duplicata Maas. 

 Cunina duplicata, Maas, 1893, Ergeb. der Plankton Expedition, Bd. 2, K.c, p. 52, taf. 5, figs. 9, 10. 



See synoptic table of species of Cunina. 



Bell 20 mm. wide, quite similar to Cunina lativentris in shape. 16 tentacles, 8 large 

 alternating with 8 small (young ?). 3 sensory-clubs on each lappet, with sensory pads above 



