NOTES ON THE JAPANESE MYOPS1DA. 



615 



scries ; horny ring of distal suckers with long blunt teeth separated 

 by distinct interspaces ; that of proximal suckers nearly entire owing 

 to close approximation of teeth. 



Hectocotylization in the distal one-third of left ventral arm, 

 normal suckers forming about seventeen transverse rows in the prox- 

 imal part. 



Tentacles shorter than dorsal length of mantle. Tentacular 

 suckers small and equal in size, arranged in eight series, with long 

 teeth in the distal part of horny ring. 



Shell very narrow, lanceolate in outline, with small discoidal 

 outer cone. Its dorsal surface strongly convex, with a arched median 

 area marked off on each side by a deep groove from lateral parts. 

 Ventral surface slightly convex anteriorly, with an irregularly running 

 median groove. Striated area marked with numerous longitudinal 

 streaks ; its anterior border deeply indented. Inner cone somewhat 

 developed, but with thin rim. Locular index about 30. 



Type. A male alcoholic specimen obtained at Kajiyama, Awa 

 Prov., Feb. 9, 1889. Dimensions as follows (paired organs measured 



on the right side) : 



mm. 



Dorsal length of mantle 231 



Ventral length of mantle 210 



Breadth of mantle 75 



Breadth of head 53 



Breadth of fin ... 13 



Length of first arm 95 



,, ,, second arm 83 



,, ,, third arm 80 



,, ,, fourth arm 63 



,, „ tentacle 190 



Diameter of largest arm-sucker 1.5 



„ „ tentacular sucker.... 0.5 



