388 DISCOVERY REPORTS 



comes to the conclusion that there is most probably only a single species of Pelagia, 

 with a world-wide distribution over all tropical and sub-tropical parts of the ocean, to 

 which the oldest name {noctiluca) ought to be applied. This comprehensive species 

 may be divided, on the base of nettle-warts and geographical distribution, into four 

 groups (cohorts) as proposed by Mayer (1910) and Krumbach (1924). It is one more of 

 the cases where the Linnean system is probably inadequate to express the relationship 

 of all the various closely related forms,united by intermediates (see Introduction, p. 333). 

 The study of the present material, containing twenty-six mostly small and young 

 specimens, presents no opportunity of reviewing this subject, the characteristics 

 of the different supposed species being still more difficult to observe in small develop- 

 mental stages than in adult animals. It rather seems once again that no distinction 

 can be based either on the size or shape of the exumbrellar nettle-warts, or on the 

 length of manubrium and mouth arms. The contraction of the bell has a considerable 

 effect on the condition of the nettle-warts, for in specimens with a flat disc-like 

 bell the warts are flat, rounded and smooth, while in others with high dome-like, 

 vaulted bell the warts are high, oblong and mostly provided with a ridge. Generally they 

 are proportionately higher in smaller than in larger specimens. Most individuals are of 

 the noctiluca type (whole surface of exumbrella covered with warts), but a few show 

 the marginal zone smooth {cyanella type, Bigelow). Moreover, in small specimens it is 

 almost impossible to state exactly the length of the manubrium in comparison with the 

 length of the mouth arms. The figures given in the table above are without any doubt 

 subject to inevitable personal error on account of the practical difficulties of 

 measurement. 



Genus Chrysaora, Per. and Les., 1809 

 Chrysaora fulgida, Reynaud 

 Syn. Chrysaora hysoscella, war. fulgida, Mayer 

 5. X. 26. 33° i' S, 17° 58' E. Hoetjes Bay, Cape Peninsula. Hand-net, o m. 

 One specimen, well preserved but a little damaged ; two specimens in pieces. 



The well-preserved specimen measures ± 220 mm. in diameter. The thirty-two 

 lappets are short, broad, and nearly semicircular. There is no difi'erence in size and 

 shape between the rhopalar and tentacular ones. The tentacular pouches are in their 

 distal parts one-third broader than the rhopalar ones. The mouth arms are rather poorly 

 folded, i^ times as long as the diameter, narrow in the middle, with the ends lancet- 

 shaped. There are twenty-four tentacles, broad, band-like and as long as the radius, 

 three per octant. The gonads are well developed, but with unripe eggs, yellowish 

 brown in colour. There is no star on the exumbrella and no pigment on the lappets 

 or mouth arms. The gonads are more pink than the tentacles, some of which are 

 brown. 



The two other specimens are so badly damaged that they have fallen into pieces. 

 They were probably larger specimens than the first, with longer richly folded mouth 

 arms; the gonads are more developed. 



