364 AKT. 2. — H. MATSUMOTO : 



together S% of the total number of Japanese species ; while the 

 three groups of Intertropical, Indo-Pacific American and Indo-Pacific 

 species unquestionably represent the tropical elements, and form 

 all together 28X of the total number. 



Among the Arctic species, three have the southern limit in 

 the Okhotsk Sea, three in the Sea of Japan northward of Sado, 

 five in the Sea of Japan off southern Korea, and four in the 

 Eastern Sea ; and along the Pacific coast of Honshu, two in the 

 Sagami Sea and Uraga Channel, four in the Yenshu Sea and 

 Suruga Gulf, and three in the Kumano Sea, off Kii. The Arctic 

 species, which occur in the Eastern Sea, appear to range through 

 the Sea of Japan, but not through the Pacific coast of Honshu. 



Among the tropical species, one has the northern limit in the 

 Strait of Formosa, two at Pinnacle Is., seven at Okinawa, one 

 at Benin Is., three in the Colnett Strait and Kagoshima Gulf, one 

 at Natsui, two in Tanabé Bay and Kumano Sea, one in the Yen- 

 shu Sea, one at Eno-ura, twenty-five in the Sagami Sea and 

 Misaki region, one at Kominato, one off Bôshû, one in the Pacific 

 Ocean far off Honshu, one off Kinkwa-san, one in British Columbia 

 and three in the Bering Sea ; and by way of the northern part 

 of the Eastern Sea to the Sea of Japan, six in the Eastern Sea, 

 five in Korea Strait and the Sea of Japan off southern Korea, 

 one off Echizen, one off Echigo, one in Hakodate Bay, two off 

 Shiribeshi and one at Wladiostok. 



Now, neglecting here the very hardy species, which have their 

 northern limit in British Columbia and in the Bering Sea, the 

 zone of mingling of the Arctic and tropical species extends from 

 off Kinkwasan to the Kumano Sea, on the Pacific side, and from 

 off Shiribeshi and Wladiostok to the northern part of the Eastern 

 Sea, on the side of the Sea of Japan. Thus, the geographical 



