418 
A. E. Yerrill — North American Cephalopods. 
beneath than laterally. Fins large, lateral. Siphon with an internal 
valve, in both sexes; connective cartilages oblong, with a central 
groove, fitting a linear ridge, on each side of the mantle; these do 
not extend to the edge of the mantle. Arms webbed for more than 
half their length, except between the ventral arms; second pair, in 
the male, and some females, with two or three much enlarged suckers 
near the middle. The suckers of all the arms are relatively larger in 
the male than in the female ; dorsal arms of the male alike ; their 
basal suckers are larger and more crowded than in the female ; no 
other evidence of hectocotylization could be found. 
Stoloteuthis leucoptera Terrill. 
Sepiola leucoptera Verrill. (See p. 347.) 
The largest specimen hitherto observed is an adult male, from 
station 947, in 312 fathoms. This differs but very little from the 
smaller male already described and figured (p. 348, PI. XXXI, fig. 5), 
but it has, on the tips of both ventral arms, four rows of small 
suckers, while all the others, of both sexes, have but two rows, even 
to the extreme tips. The suckers on all the arms of this specimen 
are decidedly larger in proportion than on the females of nearly 
equal size, and the group of larger suckers on the second pair of arms 
is represented by one very large one, on each arm. More than half 
the female specimens also have the corresponding suckers much 
enlarged, but perhaps not so much so as the males. The large males 
appear to show some evidence of hectocotylization, in having the 
suckers near the base of both dorsal arms larger and more crowded 
than they are in the females, and the portions of the web bordering 
these arms appear to be somewhat thickened or swollen, a feature not 
present in the females. But I could detect no difference in the struc- 
ture of the two dorsal arms, nor in the two ventrals. The tentacular 
arms are much swollen at base, especially the right one, while the 
club is narrower than the average width of the arm ; just at the base 
of the club, along the upper edge of the ‘ wrist’ there is a prominent 
free lobe or crest. 
In alcohol, the integument appears very thick and rather soft. In 
life there appears to be a thick, gelatinous, transparent layer, outside 
the stratum containing the chromatophores. 
The large male descinbed above, in alcohol, is 40 mm long, from end 
of body to tip of lateral arms ; breadth of body, 22 ; breadth of head, 
20; breadth across extended tins, 38 ; length of lateral arms, from 
beak, lo n,n ‘. 
