592 



MADOKA SASAKI : 



The hectocotylus is the left dorsal, as usual' in Euprymna, closely 

 resembling in its features that of E. morsel. There are in the pro- 

 ximal half of the hectocotylus about thirty small and spherical suckers 

 arranged nearly in four series and of which the three or four dis- 

 talmost of the dorsal side are larger than the others. Two nipple- 

 like protuberances project from the suckers at the ventro-proximal 

 part. The distal half of the hectocotylus is provided with about forty 

 unstalked cylindrical suckers which are a little laterally compressed 

 at their end, and are closely arranged in three or four series except 

 in the terminal parts where they are arranged generally in two series 

 (Pl. XI, fig. 6). 



7'entacles nearly as long as the mantle, sometimes much longer ; 

 stem flattened on the inner side, rounded on the outer, and the in- 

 ner dorsal angle produced into a thin membrane which distally widens 

 a little ; club not expanded, rather short, being of about one-sixth the 

 length of tentacle, pointed at the end ; suckers arranged in numerous 

 series, exceedingly small, greatly elongated at base ; not goblet- 

 shaped as in E. morsei, but very short and spherical or subcylindri- 

 cal, with minute aperture, the horny edge of which is entire and is 

 surrounded by a broad papillary area (Pl. XI, fig. 7, 8;. 



Skin smooth throughout, spotted all over with purplish brown 

 chromatophores in alcoholic specimens. Luminous organ developed 

 in mantle cavity. Gladius absent. 



Type. Male obtained at Takashima, and female at Oshoro ; both 

 May - 12, 1909; preserved in alcohol. Botli the localities are in 

 Hokkaido. 



Measurements of the types : 



Male Fe m ali 



mm. mm. 



Dorsal length of mantle (between nuchal ligament 



and posterior end of mantle) 24 33 



Ventral length of mantle 25 35 



Breadth of mantle 19 24 



