A. E. Verrill — North American Cephalopoda. 
303 
middle and directly united to the head, so as to leave no free edge 
medially, by a rather wide commissural band, the sides of which 
diverge as they extend backward within the mantle. Caudal fin 
long, narrow, lanceolate, narrowly acuminate to a very long, acute 
tip ; the anterior insertions are wide apart, and the anterior border 
is rounded. Head short and small, exclusive of the eyes, which are 
very large, globulai-, and prominent, their lower sides in contact 
beneath the head ; openings round, looking somewhat downward ; 
pupils large and round ; lids thin and simple. Siphon very large 
and prominent, extending forward between the eyes, but without a 
special groove ; dorsal surface firmly united to the head by a thick 
commissure, leaving about half the length free ; opening large, 
without any valve. 
Arms comparatively small and short, none of them complete, in 
our specimen, except those of the 3d and 4th pairs, which are nearly 
equal in length, the ventral ones a little the shortest and most slen- 
der ; the dorsal and 2d pairs of arms have lost their distal portions, 
but the parts of the dorsal arms remaining correspond in size with 
the ventral ones ; and those of the 2d pair with the 3d pair. The 
arms are all united together by a thin, delicate basal web, which 
extends up some distance between the arms (farthest between the 
dorsal pair), and then runs along the sides of the arms, as broad, 
thin, marginal membranes, to the tips. Suckers of the ventral arms 
smaller and different in form from those of the others, all of them 
being urceolate, with narrow apertures, surrounded by a slightly 
enlarged border, and having small horny rings with the edge entire, 
or nearly so, on the proximal suckers, but on the smaller ones, 
toward the tip, with a few broad blunt teeth on the outer edge. On 
the dorsal and lateral arms the basal suckers are ventricose and 
urceolate, like those of the ventral arms, but along the middle por- 
tion of these arms the suckers become much larger, and have a 
broad shallow form, with wide apertures and expanded bases ; the 
horny rings of these larger suckers are divided into several broad, 
bluntly rounded teeth on the outer edge ; toward the tips of the 
arms the smaller suckers again become deeper, with more contracted 
apertures, and with a few more prominent denticles on the rings. 
Outer buccal membrane with seven obtuse angles, and united to 
the arms by eight bridles, or commissures, of which the upper one is 
double. Exposed part of the beak black; mandibles very acute, 
strongly incurved. 
Pen very thin and narrow, and of nearly uniform width (4""") for 
more than half its length; at about four-sevenths of its length, from 
