SOME MEDÜS.E OF JAPANESE WATERS. 7 



The velarium is rather broad. In each quadrant of it are found 

 four dendritic canals. 



The genital glands are eight in number, broad, leaf-like and 

 fastened in pairs along interradial septa. The pair occupy each 

 radial pouch nearly entirely, touching each other in the middle. 



The sensory niches or cryptse rhopalares are heart-shaped 

 cavities, directed towards the oral end. The external opening 

 of each cavit}^ is furnished with a somewhat triangular lid that 

 hangs down from the aboral margin, so that the opening is horn- 

 shaped. The sensory club has two well-developed ocelli, two pairs 

 of smaller eye-spots, and a distal otolithic concretion of lenticular 

 shape and refractive nature. 



The j)edalia are oblong, leaf-shaped, with a median ridge. 

 They are about ^/s as long as the height of umbrella, and are 

 granulated in the abaxial parts. 



The tentacles are about I5- times as Ions; as the heisjht of 

 umbrella. They are of a slightly pinkish color, but all other 

 parts are colorless and nearly transparent. 



The height of umbrella is about 40 mm. 



This species is abundant in summer, near the sandy shore 

 of Tateyama Harbour at the mouth of Tokyo Bay, and is a source 

 of much annoyance to sea-bathers. It is locally known under 

 the name of " mora." 



Tanioya virulentaf n. sp. 



(PI. I, Fig. 10.) 



The umbrella is quadra ngularly prismatic with a nearly flat 

 top, about twice as high as broad. The exumbrella is granulat- 

 ed. The granules are more numerous on the top and near the 



