A, E. Verrill—North American Cephalopods. 231 
are very large, with the median more decidedly the largest, and the 
one on each side of it is shorter as compared with the next; six, on 
the inner margin, are minute, and these are connected, by one or two 
somewhat larger ones, at each end of the inner border, with the 
larger series. 
The stumps of the tentacular-arms are flattened, oval, and smooth, 
measuring about 10 by 18™™, near the base; their length is about 
28°" (11 inches), which is doubtless less than half their original 
length. 
The exposed parts of the jaws are black and polished ; the lamin 
are reddish brown, with broad, thin, yellowish-white margins. ‘The 
upper mandible has a long sharp rostrum, with regularly curved cut- 
ting edges, and a small, well-defined, V-shaped notch, from which a 
short groove runs backward, beyond which there is a slight ridge; 
anterior edge of ale, beyond the notch, forming no distinct lobe or 
tooth, but slightly convex, and irregularly crenulate ; posterior lateral 
borders of alze with a broad sinus in the middle; palatine lamina long 
and thin, with sinuous posterior margins; frontal lamina broad, ex- 
tending well backward. 
The total length of the upper mandible is 42™™; tip to posterior 
end of frontal, 33"; to notch, 10™"; greatest breadth (or height), 
from palatine to end of frontal, 30"; transverse breadth, across: 
frontal, 15"; transverse breadth, across anterior edges of alee, 8™™. 
The lower mandible has a strongly incurved beak, with the cutting 
edges rather suddenly incurved at about the proximal third, and a 
well-developed, broad, V-shaped notch at base, beyond which there is 
a slightly prominent, broad tooth ; alee broad, the inner ends broader 
than the middle, well-rounded ; mentum short, with a broad dorsal 
emargination ; gular lamina short, the inner edges incurved. 
The total length of the lower mandible is 29"™ ; tip of beak to end 
of mentum, 10"; to ventral end of gular, 21"™; to bottom of notch, 
11™"; to inner ends of ale, 24"; breadth, from inner ends of al to 
mentum, 28™"; breadth of gular lamina, 17™"; breadth of ale, 
125""; greatest transverse breadth, across ale, 32™"; transverse 
breadth, across anterior edges of ale, at teeth, 11™™. 
These jaws agree pretty nearly, in form and size, with those of O. 
pteropus, figured by Steenstrup, but the latter have a deeper notch 
in the upper mandible, with a more evident lobe beyond it, while the 
lower mandible has a broader and less triangular notch. 
The buccal membrane is large, thin, prolonged into seven acute 
angles or lobes, of which the upper is in the median plane, opposite 
