A, E. Verrill—North American Cephalopods. 213 
closely, both in form and size, with those of No. 10, the type of the 
species, but are a trifle larger. The total length of the upper man- 
dible is 133""; greatest breadth, 99"™; from inner angle of anterior 
edge to the dorsal end of frontal lamina, 95; tip of rostrum, or 
beak, to the dorsal end of frontal lamina, 92; tip of rostrum to 
bottom of notch, 19; notch to inner end of anterior edge, 38; 
transverse breadth between anterior edges, 17™™. 
The total length of the lower mandible is 95"; breadth, from 
gular lamina to ean ae of ale, 99; front edge of jaw to posterior 
end of gular lamina, 83; breadth of ale, 41; posterior edge of ale 
to end of gular ct 44°5; tip of beak Se Deen of netch, ‘22; 
notch to inner angle of ale, 70: ; depth of notch, 3°5™™, 
The general form of this species is very mel sige on Plate XX. 
This figure has been based upon the sketches and measurements 
made by me soon after the specimen was received in New York and 
before it had been “ mounted” (see page 189). The head was, how- 
ever, so badly injured that it could not be accurately figured, and 
this part is, therefore, to be regarded as a restoration, as nearly 
correct as could be made under the circumstances. It may require 
considerable corrections, both as to size and form. The caudal fin is 
remarkable for its small size, as in A. Harveyi. Its breadth is 
searcely more than that of the greatest diameter of the body. It is 
short-sagittate in form, with strongly divergent side lobes, which 
extend forward beyond their lateral insertions, and end in a rounded 
or blunt angle. The posterior end is somewhat prolonged and acute, 
but less so than in that of A. Harveyi, which it otherwise resembles. 
One of the figures (Plate XIX, fig. 2), was made by me several weeks 
after it had been placed in strong alcohol, and had shrunk consider- 
ably ; the other (fig. 1) was made by Dr. J. B. Holder after it had 
been in alcohol only a few days 
When fresh, the caudal fin was 84™ in breadth, but when sketched 
by Dr. Holder its breadth was 71%; its length, from posterior tip to 
lateral insertions, 48°3°"; from tip to end of lateral lobes, 61°™. 
The length of the body and head together, when fresh, was about 
289™ (9°5 feet); but when measured by me it was about 218. 
The sessile arms were unequal in size and length, the longer ones 
considerably longer than the head and body together. Mr. Harvey 
found that the longest arms, said to be the ventral ones, were 335°" 
(11 feet) long, and 43°2™ (17 inches) in circumference at base. 
When first examined by me the ventral arms measured 1075 feet, 
and were longer than any of the others, but all the rest were more 
