358 A. E. Verrill — North American (Jephalopods. 



anterior edge extending forward quite as far as the edge of the 

 mantle, and considerably beyond the insertion of the fin, which is 

 itself well forward. The length of the fin is about two-thirds that of 

 the body ; the base or insertion of the fin equals aboiit one-half of 

 the body-length ; the breadth of the fin is greater than one-half the 

 breadth of the body. Head large, rounded, with large and prominent 

 eyes ; lower eyelid slightly thickened. Arms rather small, unequal, 

 the dorsal ones considerably shorter and smaller than the others. In 

 the male, the left dorsal arm is greatly modified, and very different 

 from its mate. Lateral and ventral arms are subequal. 



In both sexes, and even in the young, the suckers along the middle 

 of all the lateral and ventral arras are distinctly larger than the rest, 

 but in the larger males this disparity becomes very remarkable, the 

 middle suckers (PI. XLVI, figs. 3a-3$) becoming greatly enlarged and 

 swollen, so that eight to ten of the largest are often six or eight 

 times as broad as the proximal and distal ones ; they are deep, 

 laterally attached, with a raised band around the middle, and a very 

 small round aperture, furnished with a smooth rim. In the female 

 the corresponding suckers on the lateral arms are about twice as broad 

 as the rest. The suckers are in two regular rows, on the lateral 

 and ventral arms, in both sexes. In the male, the left dorsal arm 

 becomes thickened and larger from front to back, and is usually 

 curled backward ; its suckers become smaller and much more 

 numerous than on the right arm, being arranged in four crowded 

 rows, except near the base, where there are but two ; the sucker- 

 stalks also become stout and cylindrical, or tapered, their diameter 

 equalling that of the suckers (PI. XLVI, fig. 3 ; PI. XLVII, fig. 5). 

 The right arm remains normal, with two alternating rows of suckers, 

 regularly decreasing to the tip, as in both the dorsal arms of the 

 female. Tentacular arms long, slender, extensible; club distinctly 

 enlarged, usually curled in preserved examples (PI. XLVI, figs. 2«, 3). 

 The suckers on the club are numerous, unequal, arranged in about 

 eight close rows; those forming the two or three rows next the upper 

 margin (PI. XLVII, figs. 5a-5b) are much larger than the rest, being 

 three or four times as broad, and have rows of small scale-like den- 

 ticles around the rims, the marginal ones larger. 



Color, in life, pale and translucent, with scattered rosy chromato- 

 phores. In the acoholic specimens, the general color of the body, head, 

 and arms is reddish, thickly spotted with rather large chroraato- 

 phores, which also exist on the inner surface of the arms, between the 

 suckers, and to some extent on the tentacular arms and bases of the 



