A. JE. Verrilt — North American Cephalopods. 285 
(bo) of the gills ; the anterior passing into the anterior aorta ( ao ) ; 
the posterior, median one, continuous with the posterior aorta, gives 
off, first a small ventral branch, w r hich supplies the reproductive 
organs, and then later a median ventral artery (o), going to the 
mantle ; while much farther back it divides into two branches (o', o') 
which supply the sides of the mantle and caudal fin. The branchial 
auricles (an) are large and ovate, with a small round capsule at the 
posterior end. 
The urinary organs or ‘ kidneys ’ (r, r) are voluminous, lobulated 
organs, iutimately connected with the vense cavse, and mostly situated 
below and in front of the heart, but there is a more compact glandular 
portion (r') extending, as usual, backward along each of the posterior 
venae cavae ( vc ") in the form of a long pyriform gland. Just in 
front of the bases of the gills, on each side, there is a circular opening 
(u) through the peritoneal membrane, which probably gives exit to 
the urinary excretions. 
The reproductive organs of the female, however, present the 
greatest divergence from Loligo, and allied forms. Instead of hav- 
ing a single large oviduct, on the left side only, and opening far for- 
ward, we find, in this genus, two small oviducts (ocl) symmetrically 
placed and opening much farther back. Moreover, instead of the 
large and very conspicuous, unsymmetrical nidamental glands, situated 
in front of the heart, as in Loligo , we find in Ommastrephes much 
smaller and simpler glands (xx) situated much farther back, side by 
side, near the median line. 
The ovary (ov) is a long, pyriform, lobulated organ ; its anterior 
end is attached to the posterior end of the stomach, and is divided 
into several short lobes, which clasp the end of the stomach ; its 
small posterior end extends backward into the concavity of the 
hooded portion of the pen (p"). 
The spermary or testicle of the male (Plate XXXVIII, fig. 2, t) 
occupies the same position as the ovary ; it is a more compact organ, 
with a smoother surface, and the anterior lobes are longer and 
narrower and extend farther forward along the sides of the stomach. 
The prostate gland and other male organs resemble those of Loligo 
(see Plate XL, figures 1, 2). 
It must be borne in mind, however, that none of the specimens 
examined were in their breeding season. Consequently the repro- 
ductive organs were all much smaller and less conspicuous than they 
would have been in breeding individuals. This is particularly the 
case with the ovaries and spermaries, but the same remark would 
