CEPHALOPODA OF THE HAWAIIAN ISLANDS. 



309 



tered within the bay of the ventral angle. a Funnel very large; broad at the base and tapering bluntly 

 to the wide-valved aperture. Funnel organ enormous, comprising a very large deeply bilobate pad 

 occupying most of the posterior two-thirds of the dorsal wall of the funnel, and a pair of much shorter 

 bean-shaped ventro-lateral pads. 



Fig. 31. — Sepiotsutkis arclipinnis [45]. hectocotylized portion of left ventral arm of male, X 3. 



Arms of moderate length, stout, squarish, unequal, the order of length 3, 4, 2, 1. 

 All the arms are outwardly keeled and have a broad trabeculated marginal membrane 

 bordering the sucker-bearing area, this membrane reaches its maximum on the central 

 portion of the third arms and is least developed on the ventral pair. Both outer margins 

 of the ventral arms conspicuously keeled, the dorsal keel developed as a broad thickened 

 membrane ensheathing the base of the tentacle. Suckers large, regularly alternating in 

 two rows; the homy rings of the largest armed with 25 to 26 stout acute teeth (fig. 20). 



The hectocotylization is as usual in the genus; for about 19 pairs the suckers of both 

 rows are normal; at this point on the left ventral arm the cups become suddenly reduced 

 (although persisting to about the twenty-second pair) and the pedicels correspondingly 

 enlarged; the latter continue as stout conical papillae to the tip of the arm, those of 

 the dorsal row being considerably larger than their ventral companions (fig. 21). 



Tentacles of variable length, laterally compressed; both outer and inner faces 

 subcarinate at the base, the inner becoming flattened and transversely striate distally; 

 on the distal half of the club the outer carina becomes expanded to form a heavy 

 fleshy keel. Club large, expanded; its margins bordered by a crenulate membrane 

 strengthened by rather flattened and illy-defined transverse trabecular. Suckers 

 crowded, in four rows; largest at about the middle, especially those of the two cen- 

 tral rows, diminishing toward either end; distally all the suckers become very minute, 

 those of the ventral row becoming the largest, of the dorsal smallest; horny ring of a 

 large median sucker armed with 17 to 19 strongly incurved teeth. 



Buccal membrane 7-lobed, the lobes pointed and bearing a few very minute suckers 

 near their tips. 



Gladius lanceolate; with a heavy midrib and distinct submarginal thickenings 

 (fig. 22). 



Color of preserved specimens a brownish buff everywhere beneath the large slate- 

 colored chromatophores. The latter very variable in size ; very numerous and much run together dor- 

 sally, fewer and more scattered on the ventral aspect; absent from the ventral surfaces of the fins. 



My previously published account of this structure in -S. lessoniana (1912b. p. 402) is ambiguous and very misleading respect- 

 ing the position of the olfactory pore. The pore is not really dorsal in position, but sheltered within the ventral lobe of the crest 

 as stated above. 



/ 



Fig. 22. — Sepio- 

 teuthis arcti- 



pin n is [45], 

 dorsal aspect 

 of gladius of 

 male from 

 Honolulu, 

 X l A. 



