358 
A. E. Verritt — North American Cephalopods. 
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 about 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 arms are distinctly larger than the rest, 
but in the larger males this disparity becomes very remarkable, the 
middle suckers (PI. XLYI, figs. 3«-35) 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. XL VI, fig. 3 ; PI. XLYII, 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. XL VI, figs. 2a, 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. XLYII, 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 lai'ge chromato- 
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 
