192 



APtT. 2. — H. MATSUMOTO 



mens, the disk scales are com- 

 paratively coarse and the primary 

 plates very distinct. The arms 

 are long and very slender, being 

 widest at about one-fom^th the 

 entire length from the base. The 

 dorsal arm plates are nearly as 

 wide as the corresponding arm 

 joints, and about one and a half 

 times as wide as long. The 

 ventral arm plates are slightly 

 wider than long and have a 

 notched outer border. The dorsal, 

 as well as the ventral, arm plates 

 are not in direct contact with one another, being slightly separated 

 by wedge-like prolongations of the lateral arm plates, except the 

 first two ventral arm plates, which are joined to each other. The 

 colour in alcohol well agrees with Lyman's description, but the 

 arms are irregularly banded with grayish shade. 



I am informed by Mr. Sasaki that the animals are found 

 attached to the rhizomes of Zostera marina. It is interesting to 

 find this species occurring in the northern waters of Japan, since 

 it has been known only from the eastern coast of the North 

 Pacific. 



Fig. BI. AmpMjpholis jmgetana. xl2. a. 

 From aboYe. h. From below. c. Side 

 view of three arm joints near disk. 



Amphipholis Ji'ochii Lütken. 



Ampldjyholis kochii : LÜTKEN, Oph. Nov., 1872, p. 10, PI. I & 11, fig. 6. 

 Amphiura JcocJiii : Lyman, Kep. Clialleriger, V, 1882, p. 146. 

 Numerous specimens ; Aral Beach, Misaki Biological Station. 



