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AET. 2. — H. MATSÜMOTO 



tatives of tropical fauna, and form 72X of the total, in contrast to 

 the Arctic elements, which amount to only 7%. Moreover, almost 

 all of the Honshu genera have tropical, but not Arctic, affinities. 

 Two hundred and thirty-two species of ophiurans are known 

 from Japanese waters, which may be grouped as follows. 



I. Circumpolar species, which occur in the North Atlantic, Arc- 

 tic and North Pacific. The species belonging here and their 

 known southern limits in the Nortli Pacific are as follows. 

 Species. Southern limit. 



Ophiacantha hidentata : oft' southern Korea, Sea of Japan. 



Ophiopliolis aculeata, typical : off" southern Korea, Sea of Japan. 



Ditto, including var. japonica : 

 Stegophiura nodosa : 

 Ophiiira sarsii : 



off Kii, Kumano Sea. 

 off Saghalin, Okhotsk Sea. 

 Eastern Sea ; Uraga Channel (on 

 the Pacific side). 

 4 species : 2%. 



IL Bering-American species, which range from the Bering 

 Sea to Japan and to the western coast of U. S. A. The 

 species belonging here and their known southern limits 

 in Japan are as follows. 



Species. 

 Gorgonocephalus caryi : 



Ophiophtlialmus normani : 



Amphiodia euryaspis ; 

 Ophiura cnjptolepis : 

 Ophiura leptoctenia : 



Southern limit. 

 Eastern Sea ; Suruga Gulf (on 



the Pacific side). 

 Eastern Sea ; off" Kii, Kumano 



Sea (on the Pacific side), 

 off" Korea, Sea of Japan, 

 off" Omai Zaki, Yenshti Sea. 

 off" southern Korea, Sea of Japan ; 



off" Omai Zaki, Yenshù Sea 



(on the Pacific side). 



