SOME MEDUSA OF JAPANESE WATERS. 31 



and project more or less liorizontally, while those of the other 

 kind are weakly developed and without sucker, and curve 

 downwards and inwards. Medusa-buds are produced from the 

 middle part of the four perradial canals. Closely allied to 

 the genus Gonionema. 



Scolionema ge^nmlfera^ n. sp. 



(PI. V, Figs. 32, 3.3.) 



The umbrella is more or less globular, its height and breadth 

 being nearly equal. Sixteen (four perradial, four interradial, and 

 eight adradial) larger tentacles with sucker alternate with sixteen 

 smaller tentacles without sucker. Tentacles of both kinds have 

 in their distal parts, ring-like swellings caused by the presence 

 of nematocysts. The endoderm cells at the base of tentacles are 

 greenish, while those in the distal parts are reddish. The larger 

 tentacles are nearly equal in length to the umbrella-diameter ; 

 The portion of the tentacle proximal from the sucker is nearly 

 straight, while the distal portion is bent in a crook-like manner. 

 There are eight otocysts. The manubrium has quadrate base, 

 and is light red in color, except at the narroAV mouth which is 

 of a brownish color. The velum is well developed. In the middle 

 part of radial canals, we find medusiform buds of a light red 

 color. The circular canal and the four radial canals are simple 

 and narrow. The diameter of the umbrella is 4 mm. 



In an immature specimen, about 0.7 mm. in diameter, the 

 exumbrella is found to be covered with nematocysts and to be 

 in possession of only one sort of tentacles. These are adhesive 



