Benham. — Neiv Zealand Ctenophores. 141 



guish this from B. ovata. From B. cucumis (= B. roseola, 

 Agass.) in the presence of network of canals on the wall of the 

 stomodseum — just that feature which most distinctly separates 

 the North Atlantic form from B. ovata. 



We are reduced, then, to a comparison of our New Zealand 

 species with B. ovata, which, though it descends into the tropical 

 and even the southern regions of the Atlantic, does not appear 

 to have been met with eastward of Africa. From B. ovata our 

 species differs in its more globular form, for even in the indi- 

 viduals in which the horizontal diameter is least in relation to 

 the vertical {e.g., 60 mm. x 40 mm.) the proportions are very 

 different from those of B. ovata, in which the length is more than 

 twice the breadth ; secondly, the approximation of the upper 

 ends of the subsagittal costae ; thirdly, in the cessation of the 

 costse before the lower margin is reached (which may possibly 

 be due to the specimens being not yet fully grown) ; fourthly, 

 in the fact that the mouth is not at the widest part — that the 

 lower margin of the bell is directed inwards, so that the mouth 

 is smaller, relatively, than in B. ovata. It may be that in life 

 the mouth of our species is capable of a certain amount of 

 mobility and distension. 



Reference should perhaps be made to Agassiz's* "■ Idyi- 

 ofsis clarkii " from South Carolina, which in its more rounded 

 form (see fig. 63, p. 39, loc. cit.) certainly resembles our species. 

 Agassiz emphasizes the short vertical axis, the compressed 

 body, the prominent costae, and depressed intercostal regions 

 as distinctive of the genus, which later authors include in 

 Beroe. But though there is a certain degree of resemblance, 

 it is not probable that the same species would occur in the 

 Atlantic and the Pacific. In '''' Idyiofsis darkii''^ the polar 

 area is, from Agassiz's figure, much more compact than in the 

 present species. 



The only Pacific species, besides B. australis, is Beroe macro- 

 stoma, Peron,t which was obtained south of New Guinea during 

 the voyage of the " Coquille." Its shape is, however, like that 

 of B. ovata, but Chun states that it is insufficiently described for 

 identification. At any rate it is quite unlike our New Zealand 

 species. 



Euplokamis australis, n. sp. 



The body is cylindrical, though slightly narrower at the 

 aboral pole ; the mouth is situated on a short and probablv 

 mobile tubs, considerably narrower than the body. 



* Agassiz, Illust. Cat. Harvard Mus., 1865, p. 39. 

 f Peron, Voy. de la Coriuille, Zool., p. 105, pi. xv, 2. 



