40 



1,3,4, only the two ventrals noticeably shorter than the others; each 

 with two rows of spherical, short-pediceled suckers extending for their 

 entire length. Both dorsal arms hectocotylized ; squarish, unequal, the 

 right slightly the larger; much swollen; suckers very small even at the 

 base of the arms, whence they gradually diminish in size toward the tip, 

 the two rows very regularly alternating; inner surface of each arm 

 curiously ornamented with fine transverse corrugations, striae, or wrink- 

 les, arranged more or less in bands to correspond with the bases of the 

 sucker-pedicels. Suckers of the second pair slightly larger but still quite 

 small, excepting some five pairs near the middle of the arm which are 

 greatly enlarged. Third pair of arms similar in structure to second pair. 

 Fourth pair shorter and more slender than the others, their suckers 

 mostly wanting in the specimen examined. The pedicels of all the 

 suckers, especially those of the enlarged ones, are very delicate and 

 brittle, breaking off constantly as the specimen is handled. Sucker- 

 openings very small; horny rings smooth. Arms connected at base by 

 a poorly developed web or umbrella, totally lacking between the ventral 

 pair. Dorsal arms laterally angled and with a dorsal keel; in the second 

 pair angles and keel become obsolete, reappearing again in the third 

 pair; ventral arms keeled along the outer side. 



Tentacles stout and fleshy, about as long as the mantle; the c]ub 

 furnished with a membranous keel, but otherwise not exceeding the 

 stalk in diameter; suckers extremely minute, irregularly arranged in at 

 least twelve (to 16?] rows, giving the club a velvety appearance; pedunc- 

 les slender; horny rings present. 



Color in life unknown; in alcohol a pale brown, suffused here and 

 there with blackish purple. Chromatophores numerous, appearing as 

 dark dots. As in the other members of the genus the ventral surface 

 of the mantle is adorned by a large shield-shaped patch, bordered by 

 a rather indistinct, slaty-blue margin. Over this area the chromato- 

 phores are exceedingly numerous, fine, and evenly distributed. 



Beak and radula not examined. 



Gladius absent. 



Habitat: Suruga Bay, Japan. 



Total length excluding tentacles .... 38,5 mm 



Width across fins 24 



Medio -dorsal length of mantle 17 



Medio-ventral length of mantle 20 



S. nipponeiisis is apparently very different from either of the only 

 two species of the genus hitherto known. The- generic type [S. leuco- 

 ptera Verrill, from the North Atlantici differs in its shorter arms, their 

 more complete webbing, more anterior position of fins, hectocotylization 



