60 ART. 4. 1. IK ED A : 



Pacific coasts of Japan proper, south of the Tokyo Bay. As 

 far as I know, they are exceedingly abundant in shallow parts 

 of that bay, for instance, at Inage (Province of Shimosa), Haneda 

 (Province of Musashi), and at Tateyama (Böshiu). From the 

 last mentioned locality specimens of a large size (25 cm. or even 

 30 cm. in length and 3-4 cm. in breadth) have been obtained. 

 Tomo (Bingo) and Hiroshima on the Inland Sea may also be 

 mentioned as localities where this species is known to occur in 

 great abundance. 



As to the systematic characters and the microscopical anatomy 

 of the species I have nothing to add to the exact and detailed 

 studies of Selenka and Embleton. Of much interest to me is 

 the observation by the latter author that in the present species there 

 is no true vascular canal at all — a fact which I have also observed 

 independently. 



Genus THALASSEMA. 

 THALASSEMA KOKOTONIENSE, Fischer. (?) 



(Fig. 17). 



Fischer (g), 1892, p. 2. 

 Shipley (34), 1899, p- 337. 



During a trip in 1901 to the Amami-Oshima and and Riukiu 

 Islands, I collected in all 10 specimens which I provisionally 



