.396 
A. E. Verrill — North American Cephalopods. 
more effectually, I here give a new description of the pen, based 
on these fragments, arranged as I now understand the form and 
structure. 
New description of t he pen of Arcliiteuthis Harveyi V. 
The parts preserved all belong to the posterior blade, which is 
now flattened and much mutilated, but it was very thin and broad, 
running out to attenuated borders; and it apparently had a small, 
acute, hooded terminal portion, or thin hollow cone, perhaps only 
two or three inches long, while the broad blade itself must have been 
more than two feet long and upward of a foot wide, when flattened 
out. No part of the narrow anterior shaft, which probably existed, 
is preserved. 
The extreme posterior end is gone, but the convergent ribs indi- 
cate that it tapered to a point ; each edge of the present end, for 
rather more than an inch, is thickened by a more divergent marginal 
rib, running into the edge and disappearing, while the edges here 
appear to have been toiai apart, and this portion appears to have 
constituted the hooded portion; beyond this the margins run out to 
a very thin and ill-defined edge. The midrib, or dorsal keel, is at 
first sharply angular with a triangular section, and the slender lateral 
costae are completely confluent with it, but a little farther forward 
these begin to become distinct and slightly divergent, till at about 
ten inches from the end they are about an inch from the midrib; 
except close to the posterior end, the midrib is regularly rounded, or 
nearly semi-cylindrical. Near the posterior end there are three or 
four other slightly thickened, divergent ribs, on each side, between 
the midrib and the margin, but all these, except the inner ones, soon 
run obliquely to the margins and disappear; probably these mark 
the portion that was incurved or partially hooded. The surface is 
marked by fine striae between and parallel to the ribs, but the ob- 
lique, divergent striae, so conspicuous in Sthenoteuthis , are scarcely 
apparent. The midrib has nothing of the double or grooved 
character seen in that of Sthenoteuthis and Ornmastrephes , the 
divergent ribs are much less numerous, and the whole structure is 
much more thin and flexible and the marginal portions much more 
ill-defined and membranous. 
Arcliiteuthis abundant in 1875 at the Grand Banks. 
From Capt. J. W. Collins, now of the United States Fish Commis- 
sion, I learn that in October, 1875, an unusual number of giant- 
squids were found floating at the surface on the Grand Banks, but 
