LEPTOMEDUSAE 



33 



Family Campanulariidae 



Phialidium simplex Browne 1902 



1902 Phialidium simplex Browne, p. 282. 



1939 Phialidium simplex Browne & Kramp, p. 299. PI. 17, figs. 5-9. 

 1953 Phialidium simplex Kramp, p. 272. 



Occurrence: St. 1375. 25. v. 34. 34° 30-8' S, 26° 19' E. Off the south coast of Africa. Net: TYFB 210-0 m. 

 I specimen, 12 mm. in diameter with about 48 tentacles. 



Distribution. Falkland Islands; southern part of the coast of Brazil; north-east coast of Australia. 



Phialidium discoidum (Mayer 1900) 



1900 Oceania discoida Mzyer, p. ^i. PI. 20, figs. 53-55. 

 1910 Phialidium discoidum Mayer, p. 272. PI. 33, figs. 9-11. 



Occurrence: St. 708. 23. x. 31. 10° 20' 36" S, 34° 54' 42" W. Off Aracaju, Brazil. Net: TYFB 208-0 m. 

 5 specimens. 



The specimens are almost hemispherical, 3-5-4 mm. in diameter, with 16 tentacles. The stomach is 

 small with somewhat bulging sides ; mouth with four simple lips, slightly folded. Two of the specimens 

 have well-developed gonads, one male, and one female with very large eggs; the gonads are thick 

 and cylindrical along the distal one-third to one-half of the radial canals. The 16 tentacles are of about 

 equal size, with short and broad, almost globular basal bulbs. Two or three statocysts between 

 successive tentacles. 



These specimens agree so well with Mayer's description and figures of specimens from Tortugas, 

 Florida, that it seems to me very probable that they belong to the same species. On the other hand, 

 all records of this species from the Pacific seem to me very doubtful. It is recorded from several 

 localities in Japan by Maas (1909, p. 25) and Uchida(i925, p. 90; 19276, p. 221 ; 1938, p. 42) and also 

 from the central Pacific (Uchida 1947 a, p. 304, text-fig. 6), and from the Pacific coast of Mexico by 

 Bigelow (1909, p. 155. PI. 6, fig. 8; PI. 38, figs. 6-7). All these medusae are of larger size and have 

 up to 36 tentacles, and as a rule there is only one statocyst between the tentacles. Bigelow compared 

 his Mexican specimens with specimens from the West Indies, with up to 46 tentacles, and found them 

 indistinguishable from each other. He may be right that they belong to one and the same species, 

 but I am sure that none of them belong to P. discoidum Mayer, which is a small medusa, only 4 mm. 

 wide, with 16 tentacles and usually 3 statocysts between the tentacles. Bigelow is inclined to think 

 that the difference between his specimens and Mayer's was due to the latter being young stages; 

 but according to Mayer's description and figures their gonads were particularly well developed and 

 contained very large eggs, and the same applies to the Brazilian specimens in the Discovery collection. 



Another question arises, namely, whether P. discoidum is a valid species. The summer form of 

 P. hemisphaericum from North European waters frequently attains a very similar appearance, being 

 mature at a stage with 16 tentacles and then usually with two, sometimes three, statocysts between 

 the tentacles. As a rule, however, its gonads are short and oval and not elongated as in P. discoidum. 



Distribution. Florida; northern part of the east coast of Brazil. 



Obelia sp. 

 Occurrence: St. 91. 8. ix. 26. False Bay, South Africa. Net: TYF 0-5 m. 3 specimens, c. 3 mm. in diameter. 



