ON CTENOPHORES OF THE NEIGHBOURHOOD OF MISAKI. 455 



Colour. — Transparent and almost colourless ; only the canals are 

 rosy when living. 



Specimens examined. — A number of specimens were obtained at 

 Misaki and in the Gulf of Tokyo. 



This species may be said to be the commonest ctenophore in those 

 localities. In the Gulf of Tokyo, during late-summer, the species some- 

 times swarms in such abundance that the fishermen are compelled to 

 give up using their nets, owing to the meshes becoming choked up with 

 the ctenophores. At Misaki, this species appears in large quantities 

 generally during summer and winter. After stormy weather, individuals 

 showing mark of injury in the aboral region are very commonly met 

 with. 



Remark. — MOSER, the original describer of the species, established 

 it on the basis of a single preserved specimen taken by Do FLEIN in 

 the Sagami Bay. Of the characters pointed out by her as distinctive 

 of the species, the deep situation of the sense-organ is apparently the 

 most striking. This, taken together with the unusual length of sub- 

 pharyngeal ribs, seems to afford the most important distinctive criterion 

 between this species and allied forms. The size of lappets and of 

 auricles in relation to that of the entire body varies considerably with 

 age of the animal, as in other species of the same genus. 



Genus LeilCOthea, Mertens. 



(Eucharis, Eschscholtz.) 



3. Leucothea japonica, n. sp. (Pl. VII, fig. 3). 



Body compressed, rectangular in cross-section. Tentacular axis 

 about 2/3 as long as pharyngeal axis, and slightly over 1/4 the length 

 of body proper. Lappets moderately large and about as long as body 

 proper. Auricles very long and worm-like, often coiled into helices ; 

 attached to the oral 1/4-1/3 of body. Aboral sense-organ deeply sunken ; 

 being situated at the bottom of a cleft as deep as 1/4 the length 



