HYDROMEDUSAE 279 



thirty-one tentacles. The largest number of nematocyst clusters on the tentacles was : 

 in S. hasiuelli zji, in copensis 2/1 or 3/1 ; in the type specimen of vallentmi 3/0 or 3/1, 

 in the specimens taken in 1901 usually 3/2. The relative length of the two branches of 

 the tentacles seems to distinguish S. capensis from the other species; it is, however, 

 dependent on the age of the individuals and on the state of contraction, and it is 

 evidently also subject to individual variation. In S. capensis the upper branch, when 

 fully extended, is about three times the length of the lower branch, but in a contracted 

 condition the two branches are of about equal length. In S. haswelli the upper branch 

 is shorter than the lower ; the difference in length is considerable in young specimens, 

 but very slight in the adults. In S. valle^itini the upper branch is likewise shorter than 

 the lower branch; the variations are mentioned above. 



Asexual reproduction by medusa buds is observed in young specimens of S. capensis, 

 and Briggs also records one case of very young buds being observed in a specimen of 

 S. haswelli. In S. vallentini medusa buds have not yet been observed with certainty. 



Future investigations of more extensive material from various localities will probably 

 prove that S. capensis (Gilchrist) and S. haswelli (Briggs) are identical with S. vallentini 

 (Browne). As pointed out above there are, however, certain characteristic differences 

 between these three species (the great length of the upper tentacle-branch in S. capensis, 

 the apparently limited number of tentacles in S. vallentini), which make one hesitate to 

 unite them in the present state of our knowledge. 



S. vallentini and its two nearest relatives all belong to the southern seas (Falkland 

 Islands, South Africa, and Australia). A closely related medusa is, however, described 

 from Bermuda by Weill (1937, p. 281) under the name of Elentheria (Cnidonema) 

 vallentini. It is highly probable that the identification is correct, but as only one very 

 young specimen (with medusa buds) was found its affinities cannot be stated with 

 certainty. This record, in conjunction with the four species from Hawaii, appears to 

 indicate that the distribution of the genus Staurocladia is not restricted to the southern 

 hemisphere. 



Family MARGELIDAE 



Genus Podocoryne M. Sars (1846) 



Generic characters. Margelidae with four or more simple marginal tentacles which 

 arise separately, not in clusters ; the four corners of the mouth drawn out so as to form 

 four oral arms, simple or dichotomously branched, with terminal clusters of nematocysts. 



Mayer (1910, p. 135) gives reasons for applying the name of Podocoryne Sars to this 

 genus and to relinquish Dysmorphosa Philippi, 1842. Several species formerly referred 

 to Podocoryne or Dysmorphosa belong to the genus Lizzia Forbes, 1848, which is 

 distinguished from Podocoryne by the possession of true oral tentacles arising from the 

 sides of the mouth tube some distance above the mouth opening, whereas the oral arms 

 of Podocoryne are dilatations of the corners of the mouth itself, armed with clusters of 

 nematocysts. In Podocoryne the marginal tentacles always arise separately from the 

 umbrella margin, but in some species of Lizzia the perradial marginal bulbs carry two 



