A, E. Verrill—North American Cephalopods. 247 
somewhat raised. The nuchal collar is well-marked, and slightly 
above it, on each side, is a raised epidermal ridge, from which three 
wavy, raised bands or frills, attached at their inner edge, pass ob- 
liquely backward, on each side. No cranial cartilage was observed. 
Mantle firm and dense. The neck has one median dorsal and two 
ventral facets, long, oval-shaped, with a median depressed line, but 
otherwise smooth and white; the dorsal moves on a smooth part of 
the inside of the mantle; the ventrals move on similar raised facets 
of the mantle beneath. The caudal fin was rather broad, lanceolate 
or spear-shaped, acute at tip. Gills yellowish olive, with obliquely 
transverse lamin. Gizzard, yellowish, the muscles laid like a coil of 
spun-yarn, in layers transverse to one another. 
The pen, (Pl. XXIII, figs. 4, 5,) was gone from the first specimen 
(No. 1) and broken in the others. It was found unattached, in the 
dorsal cavity. It had a thickened median rib, but becomes very thin 
at the sides, and is divided by sharp, stiff ribs or folds into three lon- 
gitudinal areas, on each side (Pl. XXIII, fig. 6). The posterior end 
is one-sided, funnel-shaped close to the tip, which is inserted into a 
long, round, thick, firm, cartilaginous cone, which tapers to a point 
posteriorly. The portion of the pen (of No. 2) preserved* and for- 
warded to me, includes all the cone and a part of the posterior end 
of the quill-portion, attached within the concavity of the cone (Pl. 
XXIV, fig. 7). The anterior end of the cone is concave and very ob- 
liquely terminated, the dorsal side extending forward some distance 
along the dorsal side of the quill. The whole length of the preserved 
cone, (doubtless much shrunken by the alcohol) is 44°5°™ (17°5 inches) ; 
of the oblique anterior termination, 15°25°" (6 inches); greatest di- 
ameter, 4°" (1°6 inches). The cone is nearly round, firm, translucent, 
brownish, or deep amber-color, and composed of numerous distinct 
concentric layers. The concavity of the anterior end firmly em- 
braces the remnant of the funnel of the quill, which has numerous 
small costz converging to the apex; two of the dorsal cost are 
much stronger than the rest, forming a strong ridge each side of the 
smaller median costa, which lies in a deep median depression or 
furrow. 
The tentacular-arms had lost their clubs; but the part remaining 
was cylindrical, 2°5 inches in diameter. The other arms were some- 
* Mr. Dall states that he attempted to dry the rest of this pen, and that of No. 3, 
but they turned brown, and then black, effloresced, and decomposed. He also states 
that the pen, when fresh, was translucent whitish, and that it changed to brownish 
yellow in the alcohol. 
