. 
REPORT OF COMMISSIONER OF FISH AND FISHERIES. [100] 
size and high development of their organs of locomotion, especially of 
the caudal fin and siphon, and for the presence of a broad, thin web 
along the lower side of the lateral arms, outside the suckers. 
The tentacular arms are, like those of Architeuthis, very long, slender, 
and provided at the base of the club with smooth-rimmed connective 
suckers, alternating with rounded tubercles, for the mutual adhesion of 
the two arms; the central part of the club is, as in Architeuthis, pro- 
vided with two central rows of large serrated suckers, and a row of 
smaller marginal ones on each side, of different form, alternating with | 
them. The lateral arms have a well-developed median crest (most de- | 
veloped on the third pair) along the outer side; on the lower inner 
angle there is a thin, membranous web, often more than twice as wide 
as the arm, along the whole length, much more highly developed than | 
in typical Ommastrephes, in which a narrow marginal membrane occurs. 
On the ventral arms the inner face is broader than on the others, and 
the two rows of suckers are farther apart. The suckers on all the sessile | 
arms are strongly denticulated on the outer side of the rim, with smaller — 
or obsolete teeth on the inner side. | 
Caudal fin very large, rhomboidal. Internal bone or pen similar to 
that of Ommastrephes, decidedly hooded at the posterior end. 
Odontophore with seven rows of teeth ; median tooth with three large 
denticles; inner lateral teeth with two eet points ; two outer lat-— 
erals ate slender. Eyes as in Ommastrephes. ' 
This group is related on one side to Architeuthis, on the other to Om- 
mastrephes. The armature of the tentacular arms will distinguish it 
from the latter, and the large caudal fin and broad membrane of the 
sessile arms from former.* The dentition of the type is peculiar, so 
faras known. In addition to the typical species, this genus will doubt- 
less include several species with marginal webs that have hitherto been 
referred to Ommastrephes, but they are often too indefinitely described 
and figured to show the special characters referred to. 
Among those that belong, without much doubt, to this genus, i in ad- 
dition to those described below, are S. Oualaniensis (Lesson), and 8. pela-— 
gicus (Bosc), and possibly O. gigas D’Orb., though the latter does not: 
have the wide lateral membrane on the nha 
Sthenoteuthis megaptera Verrill.—(Large Broad-finned Squid.) 
Architeuthis megaptera Verrill, Amer. Journ. Sci., vol. xvi, p. 207, 1878. 
Tryon, Manual of Conchology, vol. i, p. 187 (description copied from preced- : 
ing paper). ; 
Sthenoteuthis megaptera Verrill, Trans. Conn. Acad., vol. v, pp. 223, 286, pl. 21, 
figs. 1-9, pl. 27, fig. 6, pl. 45, figs. 5, 5 a, 1880-81 ; Amer. Journ. Sci., vol. 
xix, p. 288, 1880. 
Plate XVI, figs. 1-10. 
Although very much larger and stouter than any of the ordinary. 
squids, this species is much smaller than the species of Architeuthis, the 
* According to the statement of Gervais, Architeuthis dux has similar membranes. 
