[231] CEPHALOPODS OF NORTHEASTERN COAST OF AMERICA. 
Figure 6.—Tlie same specimen. Connective cartilage from the base of the siphon; 
natural size. 
Figure 7.—The same specimen. Transverse sections of some of the arms ; a, of dorsal; 
b, of second pair; c, of third pair; natural size. The suckers are omitted. 
Figure 8.—The same specimen. Rings of suckers of the sessile arms, enlarged 2 diam¬ 
eters ; a, a', side and front views of the 15th and 13th suckers of a ventral arm ; b, b', 
side and front view of one of the largest suckers of a lateral arm; c, e', side and 
front views of one of the larger suckers of a dorsal arm. 
Figure 9.—The same specimen. Part of the border of one of the larger suckers (12th) 
of the second pair of arms; more enlarged, showing part of the dentate edge of the 
horny ring, with a portion of the circle of small plates, attached to the membranous 
border. 
Figures 4 and 7 are by the author; fig. 4 is a camera-lucida drawing. 
Plate XVIII. 
i 
Figure 1, la.— Ommastrephes illecebrosus V. Young male from Provincetown, Mass. 
General figure of ventral side; £ natural size; la, club of the right tentacular arm, 
front view; If natural size. 
Figure 2.—The same. Club and part of tentacular arm, of a larger female specimen; 
enlarged If diameters. 
Figure 3, 3a.—The same. Hectocotylized right ventral arm of a large male specimen, 
from Eastport, Me., showing the sexual modification of the suckers and their 
peduncles toward the end of the arm; 3a, transverse section of the modified por¬ 
tion of the same. 
Figure 4.—The same. Pen of a young specimen; f natural size. 
Figures 5 and 5a.—The same. Side and front views of a large sucker of the lateral 
arms; enlarged f diameters. 
Figures 6 and 6a.—The same. Side and front views of a smaller distal sucker of the 
lateral arms; enlarged fj diameter. 
Figure 7.—The same. $ . Side view of the horny ring of one of the largest suckers 
of the club; enlarged 3f diameters. 
Figure 8.—The same. From Eastport, Me. Part of the teeth of the odontophore, in 
their natural positions; enlarged 10 diameters; a, median teeth; b and b', inner lat¬ 
eral teeth; c, middle lateral teeth; d, outer*lateral teeth. 
Plate XIX. 
Figure l.— Ommastrephes illecebrosus. Male, f natural size. Opened on the ventral side. 
The peritoneal membrane, most of the renal organs on the right side, and the repro¬ 
ductive organs, except the testicle (t), have been removed. M, mantle cut open; 
F, caudal fin; P, posterior part of pen; S, stomach; S', ccecal lobe; H, systemic 
heart; c, the eye; b, olfactory or nuchal crests; d, siphon; f,f, connective cartilages 
on the base of the siphon; connective cartilages of the mantle, which fit into 
f,f; in', lateral muscles of neck; g, g, gills; 1, liver; i, iuk-sac; h, intestine or rec¬ 
tum; ao, anterior aorta, going to head ; bo, efferent branchial vessel; o, median ven¬ 
tral artery of mantle; o', o', lateral arteries going to mantle and fins; a u, branchial 
auricles; v c, anterior vena-cava; vc", posterior vena-cava of left side (the right one 
has been removed); r r, saccular ventral renal organs; r', more compact glandular 
(renal) organ, connected with the posterior veme-cavte; t, testicle or spermary; p", 
hooded posterior tip of pen, inclosing the end of the spermary. From an alcoholic 
specimen. 
Figure 2.—The same. Jaws; enlarged 14diameters; a, superior; b, inferior mandible. 
Figure 3.—The same. Part of the teeth of the odontophore in their natural positions, 
enlarged 25 diameters; a, median teeth; b and b', inner lateral teeth; c, middle lat¬ 
eral teeth; d, outer lateral teeth. 
