ON CTENOPHORES OF THE NEIGHBOURHOOD OF MISAKI. 467 



canals. The location of gonads is noteworthy. The ovaries, situated 

 on the perradial side of meridional canals, are developed on the wall 

 of those canals as well as on that of the basal parts of the canalar 

 branches of the same side. The testes develop on the interradial side 

 of the canals and also in special simple or branched blind-tubes arising 

 at positions more external than ordinary canalar branches of the side. 

 Some of the branches from the marginal canals around the mouth also 

 contain sexual elements ; this is especially the case in those branches 

 occurring on the narrower sides of body. All the parts of canalar 

 branches, in which the gonads are contained, become swollen and are 

 conspicuous on account of their milky colour. 



Colour. — Transparent and almost colourless, or slightly pinkish, 

 especially along meridional canals and their larger branches. The 

 gonads appear milky white, as indicated above. 



Specimens examined. — A number of specimens were studied in the 

 living state and also after preservation : One (1. 62 mm.) from Misaki, 

 Dec. 30, 1916 ; thirty eight (1. 1.5-42 mm.) from Tokyo Bay, Sept. 2, 

 191 7 ; one large specimen from Tateyama Bay, April, 191 3. 



This seems to be one of the commonest ctenophores in the waters 

 of the neighbourhood of Misaki. On Sept. 2 of last year, very large 

 swarms of the species were met with in the Gulf of Tokyo. 



Remark. — It is not impossible that Moser's B. hyalina (1907, p. 

 450 ; 1908, p 27, PI. i, figs. 4, 5) is identical with this species, sharing, 

 as it does, with the latter the identity of locality, the simpleness of 

 pharyngeal canals as well as the delicacy of body texture. Neverthe- 

 less, the description given by her of that species does not accord well 

 with the characters of the present form in the following important 

 points : The location of gonads, as given by her for B. hyalina, is 

 entirely different ; all the intervals between ribs are said to be nearly 

 equal, all the ribs to be of the same length, and the marginal canals 

 to be without branches. Now, eight specimens before me of about the 

 same size (1. 10-16 mm.) as those which were at Moser's disposal (1. 11- 



