ICO 



MADOKA SASAKI. 



backward beyond posterior end of mantle ; both together of a transversely 

 oval shape, slightly notched at the anterior attachment as well as in the 

 middle of their combined posterior edge. 



1 lead large, as broad as mantle-opening. Siphonal groove shallow, 

 marked by a faint boundary fold ; neck with distinct boundary edge in 

 front, and with a minute papillär}' organ on each side. Eyes large, eye- 

 opening nearly round, with an indistinct shallow notch at the anterior edge ; 

 left eye-opening very large, being twice as wide as the right. Siphon 

 short, extending for about one-fourth the length of head, its dorsal 

 connective ligaments imbedded under the skin of siphonal groove. 



Arms very long, thick ; subequal, the order of length being 2^>3)>4^>r 

 in the female specimen (no. iii) of 97 mm. mantle-length ; the longest pair 

 about thrice as long as mantle. The umbrella in the same female specimen 

 extends for a distance of 26 mm. from the angle between dorsal arms, 

 24 mm. between first and second pairs, 20 mm. between second and third 

 pairs, 15 mm. between third and fourth pairs, and 10 mm. between 

 ventral arms. Protective membrane of arms thick and choroidal, with 

 zigzag edge-line, about half as broad as the suckers are high. Suckers 

 nearly spherical, arranged in two series, the largest in the middle parts 

 of arms and growing smaller towards both arm ends ; suckers of the 

 fourth pair of arms much smaller than those of all other arms, being half 

 as large in diameter as the latter. 1 Iorny rings with quadrangular teeth 

 thickly arranged along their distal margin, the number of teeth in speci- 

 mens Nos. i and ii varying from six to eleven, and in specimen No. iii 

 from eight to nineteen. In the last specimen the horny rings often bear 

 irregular horny masses, which sometimes entirely cover up the teeth. 



Both the arms of dorsal pair are hectocotylized, their principal 

 ■characteristics agreeing well with the account given by Chun (1906, 1910). 



The tentacles of this species have hitherto been quite unknown. 

 Their length is about equal to four times the mantle-length ; the stem in 

 the distal parts is a little compressed, with a flat inner surface. Club 

 lanceolate, of about one-seventh the length of the entire tentacle, provided 

 with a web along the distal two-thirds of the length of its outer surface ; 



