414 
A. E. Verrill — North American Cephalopoda. 
but similar in form, deep cup-shaped, convex in the middle, obliquely 
attached, with a smooth horny rim, except on the distal ones, which 
have blunt denticles externally. There are about sixteen of these 
suckers on each of the lateral arms, but eight or ten are decidedly 
larger than the rest. The large suckers commence nearly at the mid- 
dle of the arms and extend to very near the tips. The suckers on all 
the arms are deep, urceolate, with somewhat contracted apertures ; 
they mostly have the horny rim entire; the distal ones on the ventral 
arms are finely denticulated. The third pair of arms have a thin 
median earina on the outer side, along the distal third. 
All the arms have a wide marginal or protective membrane along the 
inner edges, outside the suckers; these membranes are strengthened 
by transvere thickened, muscular processes, opposite each sucker; be- 
tween these the membrane recedes so that the edge is scolloped. The 
ventral arms have also a membrane along the outer, ventral angle. 
I am unable to detect any positive signs of hectocotylization, either 
in the dorsal or ventral arms. Perhaps the presence of the very large 
suckers on the lateral arms may be a sexual character, but if so, they 
are symmetrical on the two sides. 
The tentacular arms (PI. LYI, fig. 3) taper from the thickened base, 
and in our specimens equal in size, and are not much longer than, those 
of the third pair; club well developed, rather broader than the rest of 
the arm, with a dorsal keel and wide, marginal, protective membranes; 
the suckers are arranged in four regular rows; the larger suckers are 
about equal in size to the larger ones of the dorsal arms ; of these 
there are eight or nine in each row, the marginal ones are scarcely 
smaller than the median ones and similar in shape, but more oblique; 
all these suckers are cup-shaped, obliquely attached, with long pedi- 
cels; the marginal ring is denticulated all around, the teeth on the 
outer or higher side being slender, sharp and incurved; those on the 
inner side minute. The distal part of the club is short, and covered 
with four rows of small suckers, similar to the larger ones in shape 
and armature; at the tip is a small group of minute suckers, appar- 
ently unarmed. At the proximal end of the club there is a group of 
small denticulated suckers; and four irregular rows of minute, con- 
nective suckers, attached by short pedicels, extend along the inner 
surface of the arm to the middle or beyond ; these are interspersed 
with minute tubercles, more distinct distally, near the club. The 
outer buccal membrane is narrow, without distinct angles. 
The pen is very thin, delicate, pale yellow; the anterior portion is 
very narrow and slender; the posterior third, commencing opposite the 
