232 A. E. Verrill — North American Cephalopods. 



tlie interval betAveeii the dorsal arms ; the six others are opposite the 

 three other pairs of sessile arms. The inner surface of this membrane 

 is covered, near the periphery, with small rounded papilla?; externally 

 it is connected to the arm by seven membranous bridles, correspond- 

 ing to the seven angles ; of these the dorsal one forks, one branch going 

 to the inner margin of each dorsal arm; the upper lateral ones join 

 the marginal membrane of the upper angle of the upper lateral arms ; 

 the lower lateral ones join the lower marginal membrane of the third 

 pair of arms; the ventral ones join the marginal membrane outside of 

 tlie sucker-bearing face of the ventral arms. In front of the bases of 

 each of the doi'sal and tentacular arms there is a large opening to the 

 space beneath this membrane. 



The beak is closely surrounded by a thick, prominent, lobed and 

 wrinkled, fleshy collar, with papillae on its inner surface ; outside of 

 this there is a smooth, sharp-edged, erect collar, less prominent than 

 the inner one. 



The odontophore is similar to that of Omniastreph.es ; it is sharply 

 bent upon itself anteriorly, with the ventral end less than half as long 

 as the dorsal ; the dentigerous zone is yellowish brown in color and 

 bordered laterally by a thin ridge formed by a row of small plates ; the 

 lateral membrane is broad, thin, and pale yellow, running straight 

 across, from the ventral end, at right angles to the dorsal portion, and 

 then folding back upon itself, joins the dorsal part of the odontophore 

 farther back, near its middle ; beyond this point it is very narrow and 

 rolled in. Length of the dorsal })ortion, 19™'"; of the ventral, 9; 

 breadth of the dentigerous zone, anteriorly, 5""" ; breadth of mar- 

 ginal membrane, anteriorly, 7'"'". 



The median teeth are broad, with three stout points, the middle 

 one nearly twice as long as the lateral ; the inner lateral teeth are 

 much longer, with one long stout point and a short denticle on the 

 outer side, below the middle ; the two outer rows have simple, long, 

 and rather stout, curved teeth, those of the outermost row a little 

 longer and narrower than the others. The teeth differ decidedly from 

 those of S. megaptera in the shortness of the lateral denticles of the 

 median and inner lateral teeth ; moreover all the teeth are stouter and 

 less acute. 



The pen resembles that of Omraastrephes ; it is long, widest ante- 

 riorly, bordered by strong ribs, obtusely pointed at the anterior end, 

 gradually narrowing to the very narrow slender portion, about three 

 inches from the posterior end, beyond which there is a thin margin, 

 M'hich expands into a lanceolate form, widest at 1*25 inches from the 



