A. E. Verrill — North American Cephalopods. 223 



large denticles ; inner lateral teeth with two unequal points ; two 

 outer laterals simple, slender. Eyes as in Ommastreplies. 



This group is related on one side to Architeuthis, on the other to 

 Ommastrephes. The armature of the tentacular-arms will distinguish 

 it from the latter, and the large caudal iin and broad membrane of the 

 sessile arms from the former.* The dentition of the type is peculiar, 

 so far as known. In addition to the typical species, this genus 

 will doubtless include several species with marginal webs, that have 

 hitherto been referred to Ommastrephes; but they are mostly too in- 

 definitely described and figured to show the special characters referred 

 to. Thus, O. pteropus Steenstrup belongs to this genus, if a specimen 

 from Bermuda, now in ray possession, be correctly identified. f 



Sthenoteuthis megaptera Yeniii. 



Architeuthis megaptera Verrill, Amer. Journ. Science, vol. xvi, p. 207, 1878. Tryon, 

 Manual of Conchology, vol. i, p. 187 (description copied from preceding paper). 



Plate XXI, figures 1-9. 



Much smaller than the species of Architeuthis, the total length 

 of the body and head being but nineteen inches. Body relatively 

 short and thick. Caudal fin more than twice as broad as long, the 

 length about half that of the body. Its form is nearly rhombic, with 

 the lateral angles produced and rounded, and the posterior angle 

 very obtuse, the posterior edge, as preserved, being slightly concave. 



The ventral anterior edge of the mantle is concave centrally, with 

 a slight angle to either side, about '15 inch from the center; from 

 these angles it is again concave to the sides ; on the dorsal side the 

 edge advances farther forward than beneath, terminating in a slightly 

 prominent, obtuse angle in the middle of the dorsal edge. The ex- 

 ternal ear consists of a slightly elevated, transverse lamina, with three 

 thicker and much more elevated lamina? which extend forward, on 

 the head, one in the median line of the eye, with one above and one 

 below it, the lower one longest and least elevated, curving downward 

 beneath the head. The two upper ones are broadly rounded at top. 

 Behind the transverse fold there is a deep, irregularly crescent-shaped 

 fossa. The eye-sockets are large, oblong, and furnished with distinct 



* According to the statement of Gervais, Architeuthis dux has similar membranes. 



f S. Sartramii (Ommastrephes Bartramii (Leach) D'Orb.) also belongs to this genus, 

 but is a more slender species. It has the characteristic smooth suckers and tubercles 

 on the wrist of the ' club,' and a very broad caudal fin. It lives in the region of the 

 Gulf Stream. 



