444 MEDUSiE OF THE WORLD. 



lappets and these anastomose so that there are only 13 near the center of the exumbrella. 



These ridges are pigmented with brownish-purple. The bell and tentacles are bluish-violet. 



Indian Ocean, east of Zanzibar. 



Pegantha dactyletra Maas. 



Pegantha dactyletra, Maas, 1893, Ergcb. der Plankton Exped., Bd. 2, K.c, p. 47, taf. 5, fign. 1-8. 



Bell thick, doubly convex, 25 to 30 mm. wide. The exumbrella displays 32 ridges which 

 radiate outward in the radii of tentacles and lappets. 16 solid tentacles alternating with 16 

 five-angled marginal lappets. 5 to 7 sensory-clubs on outer margin of each lappet. Stomach 

 wide and lenticular, the mouth a wide, round opening with thick margin. These occupy the 

 middle of the subumbrella side of each lappet. Each gonad is a large sac-like body, which in 

 turn gives rise to about 5 somewhat irregular finger-shaped diverticula. The 16 wide, marginal 

 loop-canals extend outward from the central stomach and loop around the margin of each gf 

 the 16 lappets. These insertions of the tentacles lie between the places of origin of each 

 adjacent pair of loop-canals. 



A single specimen was found by the Plankton expedition on the surface on August 22, 

 1889, in the middle of the Atlantic in about N. lat. 28°. Maas sectioned the medusa, thus 

 demonstrating the presence of a marginal canal system. (See text-fig. 298.) 



Pegantha laevis H. B. Bigelow. 



Pegantha laevis, Bigelow, H. B., 1909, Mem. Museum Comp. Zool. at Harvard College, vol. 37, p. 97, plates 16, 20, and 27. 



This form resembles P. dactyletra Maas in its gonads, sensory-clubs, and form of lappets 

 but its exumbrella is plain and without the sculpturing seen in P. dactyletra. Bigelow's 

 specimens of P. laevis were 28 to 41 mm. in diameter and had 16 to 22 tentacles. 



Bigelow found that solid, ciliated, stolon-like larvae, or buds, are budded off from the ento- 

 derm of the ring-canal, the ectoderm apparently taking no part in their formation. Tropical 

 Pacific, Hawaiian Islands to the coast of Peru. 



Pegantha sieboldii. 



Pegasia sieboldii, Haeckel, 1879, Syst. der Medusen, p. 331. 



Bell crown-shaped, 20 mm. wide, 10 mm. high. 12 tentacles, each twice as long as bell- 

 diameter. 12 oval lappets alternate with the 12 tentacles. 16 to 18 sensory-clubs upon each 

 lappet, 200 to 220 in all. The inner ring of gonads is small and simple, bending convexly out- 

 ward between tentacles. The outer gonad consists of 12 half-moon-shaped pouches in the 

 upper third of each subumbrella lappet saccule; each of these half-moon-shaped gonads is 

 divided by three radiating furrows into four minor lappets, the two median of which are twice 

 as large as the two outermost. 12 deep, radiating furrows arranged in pairs on the exumbrella. 

 The description is based upon a single specimen studied by Haeckel and found in the tropical 

 Atlantic. It is probably identical with Pegantha dodecagona Peron and Lesueur. 



Pegantha dodecagona Pe'ron et Lesueur. 



Pegasia dodecagona, Peron ei Lesueur, 1809, Ann. Mus. Hist. Nat. Paris, tome 14, p. 341.— Blainville, 1S34, Manuel 

 d'Actinologie, p. 281, plate 33, fig. 2. — Haeckel, 1879, Syst. der Medusen, p. 331. 



Bell 40 mm. wide, 12 mm. high, cap-shaped, with smooth exumbrella surface, ^ten- 

 tacles, each as long as bell-radius. 12 semicircular lappets alternating with the 12 tentacles. 

 10 to 12 sense-clubs on each lappet, 120 to 140 in all. The inner gonad is a small, simple ring, 

 while the outer one consists of 12 simple, large, egg-shaped sacs, each one ot which arises 

 from the subumbrella floor of the stomach in the radius of a lappet. This species is found 

 in the south Atlantic. The best description is that of Haeckel who studied an original speci- 

 men in Pcron's collection. Are these two systems of gonads so sharply separated as one 

 would be led to suppose from Haeckel's description ? 



Pegantha punctata. 



/Enuorea punctata, Quoy et Gaimard, 1824, Voyage de 1' Uranie, Zool., p. 564, plate 85, fig. 4. 

 Solmaris punctaius, Haeckel, 1879, Syst. der Medusen, p. 356. 

 ( ?) Solmaris astrozona, Haeckel, Ibid., p. 357 (China Sea). 



