On Thy sail ostonia denscrispinn, nov. spec- 



By 

 K. Kishinouye. 



Zoologist to the Department of Agvicultare and Commevce. 



(With PL XVIII.J 



On July 'iOfch, 1894, a bsaatifal Ehizostomatoas medusa was 

 obtained at a small creek near the Marine Biological Station in Misaki. 

 It was preserved in alcohol and kindly put into my hand for identification 

 by Prof. Ijima. This seems to be a rare species in the above mention- 

 ed locality, as it is the only specimen as yet observed. 



The umbrella is very high, higher than semispherical, about 73 times 

 as high as broad. It is about 40 mm. in breadth. Mr. H. Nakagawa who 

 sketched this medusa from life tells me that the umbrella was larger and 

 much higher in the fresh state, its height and breadth having been almost 

 equal. From the water color sketch of Mr. Nakagawa and also from 

 Prof. Ijima's notes on the label, we know that the umbrella was 

 beautifully violet and the marginal lobes hazel-brown. 



The exmiibrella seems granular, as it is divided into very minute 

 polygonal areas. In the central portion of the subumbrella we find the 

 genital gland, the gastric cavity and the mouth arms, and in the peri- 

 pheral portion the muscle-plate is well-developed with many contmual, 

 circular ridges (fig. 3). 



The margin of the umbrella is cut into 72 lobes. In each octant 

 there are 6-9 velar lobes between 2 ocular lobes, (figs. 1, 2). The velar 

 lobes are truncate and rounded. The ocular lobes are also rounded ; but 

 as their two lateral sides are turned inward, they seem triangular and 

 pointed. 



