A, E. Verrill— North American Cephalopods. 229 
lateral insertions, 5°" (2 inches); breadth of body, 11°9°"; circum- 
ference of body, 29°2°" (11°5 inches). 
The body is stout, acuminate posteriorly ; the anterior border of the 
mantle, beneath, is even, and not distinctly emarginate in the middle. 
The caudal fin is large, broad, transversely rhomboidal, but neither 
so broad nor so large proportionally as in S. megaptera. The siphon 
is very large and broad, (68"" long by 50 broad), with a large aper- 
ture, 25™" wide. The eye-balls are very large, elongated, measuring, 
although somewhat collapsed, about 42™" long by 31™™" broad. The 
eye-openings, as distended, are large, oblong, elliptical, with a broad 
sinus, and slightly thickened edges. 
The arms are stout and rather long, the third and ventral pairs 
being nearly equal in length; those of the second pair are about 
12°5™™ shorter than those of the third; the dorsal ones about 63™™ 
shorter than those of the second. The dorsal arms are 18:4 long, 
trapezoidal in form, the outer face convex and about 1:9 broad ; 
the lateral and inner faces, 1:2°"; along the inner angles there is a 
narrow membrane, outside the suckers. Those of the second pair are 
24-7 in length; their transverse breadth is about 2™,; from inner 
face to outer angle, 1°9°"; along the outer angle, in these, is a thick 
acute-edged crest, widest in the middle of the arm; along the lower 
inner angle, outside the suckers, there is a broad and very thin mem- 
brane, 2°5°" or more in width; along the upper inner angle, is a 
similar membrane, about ‘6° wide. 
The arms of the third pair are 26 long, (31° from center of eye 
to tip of arms); they are compressed, 2°25 broad at base; on the 
outer angle, along the middle, there is a very prominent crest, so 
that, in this part, the distance from inner face to outer angle, is 4°"; 
along the lower-inner angle there is a very broad, thin, delicate web, 
where widest at least 5 to 7°" (2 to 2°75 inches) wide, (it is consider- 
ably torn and may have been still wider); it is widest beyond the 
middle of the arm; on the upper-inner angle the corresponding mem- 
brane is about 0°6° wide. Transverse, thick, fleshy ridges run out 
from between the suckers a short distance on these membranes, and 
then fade out. The ventral arms are 2°25 broad at base, and trape- 
zoidal ; they have a smaller crest along the outer angle, and a narrow 
membrane along each inner angle. 
All the sessile arms bear similar suckers, all of which are provided 
with 7 to 13 large, very acute, incurved teeth on the outer margin of 
the very oblique, horny rings, and with much smaller, sometimes 
rudimentary ones on the inner margin, much as in S. megaptera. 
