272 
A. E. Verrill — North American Cephalopoda. 
The portion of the tentacles which bears suckers is always less 
than half the whole length. The relative size of the suckers varies 
greatly in both sexes, perhaps in connection with a periodical 
renewal of their horny rings. 
The club is long and moderately broad, gradually widening from 
the peduncular part of the arm, and tapering at the end to a rather 
blunt, flattened and curved tip, which is strongly carinated on the 
outer side by a thin lamina. The suckers commence a short distance 
in advance of the expansion of the club. They are at first small, 
deep cup-shaped, and somewhat scattered, in two alternate rows, but 
all of these small ones have oblique rims, strongly denticulated 
on the outer margin with four or five long incurved teeth, while the 
inner edge is smooth. Of the small ones, before the commencement 
of the two median rows of large suckers, there are from ten to fifteen. 
The middle region of the club is occupied by two rows of large 
suckers (fig. 7) and by a row of small marginal ones, on. each side, 
alternating with the large ones. The uppermost of the two rows of 
large suckers contains one or two more suckers than the lower, and 
they are also larger. The number in the upper row is seven to nine, 
in the lower five to seven, the largest specimens having the greater 
number. Of these, the three to five middle ones in each row are 
decidedly the largest and have the edge of the marginal ring nearly 
smooth and even ; at each end of each row the suckers diminish in 
size and the edge becomes denticulate, at first by the formation of 
narrow incisions, which leave broad, stout, blunt denticles ; but as 
the suckers diminish in size these become longer, narrower and more 
acute ; their inner margins remain smooth. The large suckers are 
broad and moderately deep, somewhat swollen below, and a little 
oblique. The marginal suckers are much smaller, shallower, more 
oblique, and have the entire rim finely and sharply denticulate, the den- 
ticles being longer and strongly incurved on the outer margin. Beyond 
the rows of large suckers there is, at first, a small group of sharply 
denticulate suckers, in four rows, resembling the marginal ones in 
form and size ; but these rapidly decrease in size and are succeeded 
by eight crowded rows of very small suckers, with minute apertures, 
which occupy the entire face of the terminal section to the tip. 
The suckers of the sessile arms are largest on the two lateral pairs, 
on which they are nearly equal, and the largest are about the same 
in size as those on the tentacular-club ;* those of the ventral arms are 
smallest ; those of the dorsal arms are intermediate in size between 
* In the males the tentacular suckers are usually the smaller ; in the females often 
the larger. 
