186 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.57. 



Station Sado Island. One female. Cat. No. 332877, U.S.N.M. 



This species has not been fuUy described in English so that a descrip- 

 tion of it here seems to be advisable. 



Mantle purse-shaped, a little longer than broad; anterior margin 

 connected with the head at the nape by a commissural integument 

 narrower than one-thu-d the body-breadth; ventral edge em.arginated 

 crescentwise, the excavation marked off by projections. Fins semi- 

 lunar or subovate, about five-sevenths as broad as long, and h-j as 

 long as the body; auriculated anteriorly, attached to the dorso-lateral 

 surfaces of the body at the middle of its length. 



Head as wide as, or even broader than body; v/ith large full eyes 

 which form an incompletely circular lid-fold ventrally. Umbrella ill 

 developed except between third and fourth arms, where it extends 

 about a quarter up the arms. Fimnel slender, extending less than 

 to interbrachial space, clearly marked off throughout, widely conical 

 at base and tubular distally. Funnel organ composed of a trian- 

 gular dorsal pad and two elliptical ventral pads. Funnel cartilage 

 oblong, a little longer than three times its ov.oi breadth. 



Ai'ms subequal, the formula of length being 2=3>4 = 1, the 

 longest about as long as the body. Third pau" in mature males pecul- 

 iarly thickened in the proximal parts, attenuated in the distal, and 

 strongly curved into the shape of an S. Suckers biserial, numbering 

 about 25 pairs on each arm; in the female, small and comparatively 

 uniform; in male, unequal, largest at the middle of arms but uniform 

 in first arms and rudimentary in the third. 



Left dorsal arm prominently hectocotylized, |-f as long as the 

 right dorsal; thickened, terminating abruptly. On the base of the 

 arm, there are found four or five minute suckers, followed by a 

 large rounded swelling on the ventral side; the swelling produces 

 two conical sharply pointed recurved rostra, of which the anterior 

 one is usually much larger than the posterior. The rcmaming part 

 of the arm has about 40 papillae tightly palisaded in two rows and 

 bearing minute suckers on their tips. 



Tentacles slender, decidedly thmner than any of the arms, and 

 twice as long as the ventral arms. Club about one-fourth the entire 

 length of tentacles, slightly expanded, flattened, with very narrow 

 dorsal web. A broad semilunar membrane is present on the dorsal 

 side of the carpus. Suckers equally minute, shallow, numbering only 

 four in a row at the base of the club but about sixteen in a row at 

 its subterminal part; horny ring with about twenty blunt separate 

 teeth. 



Saddle-shaped luminous organ well developed. Spermatophores 

 about 13 mm. long. 



Mantle length 8-15 mm. in males, 8-14 mm. in females. 



