A. E. Verrlll — North American Cephalopods. 289 



Sthenotenthis Bartramii Verriii (continued). 



Sthenoteuthis Bartramii Verrill, this volume, p. 223, Feb., 1880; Amer. Journ. 



Sci., xix, p. 289, Apr., 1880. 

 Ommatostrephes Bartramii Steenstrup, Oversigt Kongl. D. Vidensk. Selsk. For- 



handl, 1880, (received Aug.), auth. sep. copy, p. 9, fig. 2, p. 11. fig. 3, p. 19. 



Body cylindrical, elongated, slender, tapering but little in front of 

 the fin ; anterior edge of mantle with a very slight, median dorsal 

 angle. Caudal fin short and transversely rhomboidal, with the outer 

 angles acute, posterior angle obtuse, and the front edges rounded 

 and projecting forward beyond the insertion. Length of fin (from 

 insertion) to its breadth, as ' : 2 ; length of fin to mantle, as 1 : 2*80, 

 in a young female specimen with the body 3 "25 inches long. Head 

 short, as broad as the body ; eye-opening angular, higher than long, 

 with a narrow oblique sinus. Nuchal frills nearly as in O. illecebrosa, 

 consisting of a low, transverse, undulated ridge extending around both 

 sides to the dorsal line, and with three raised longitudinal mem- 

 branes on each side. Siphon large, sunken in a deep pit ; anterior 

 border of the pit with a series of 6 to 12 or more (variable with age), 

 small and short furrows, which extend inward only a short distance 

 from the edge. Arms rather short, not very unequal ; the dorsal 

 ones are a little the shortest and smallest ; the third pair are the 

 longest, the second and fourth pairs are intermediate in length, and 

 nearly equal ; the arms of the second pair are furnished with a well- 

 developed membrane along the lower outer angle, and with a thin 

 marginal membrane of moderate width along the inner angles, out- 

 side the suckers, that on the lower side extending beyond the 

 suckers. Those of the third pair are compressed, with a well-devel- 

 oped membranous keel on the median outer edge, beyond the basal 

 portion ; on the lower inner angle there is a broad, thin, marginal mem- 

 brane, extending beyond the suckers, and a narrow one on the upper 

 side ; the dorsal and ventral arms have narrow marginal membranes. 

 Suckers of the dorsal and lateral arms furnished with horny rings 

 which have the edge divided into small, acute-triangular teeth, 

 largest on the outer side ; on the ventral arms the suckers are 

 smaller, those on the proximal half of the arm having smooth-edged 

 rings, while those on the distal portion are sharply toothed on the 

 outer edge. Tentacular arms slender and moderately elongated, 

 with distinctly broader clubs, which are keeled on the back, side and 

 furnished with a thin marginal membrane on each edge. The suckers 

 consist of two median alternating rows of larger oblique, dentate 

 suckers, of which seven to nine in each row are decidedly largest ; 



