[127] CEPHALOPODS OF NORTHEASTERN COAST OF AMERICA. 337 



long, slender, acute tail ; mantle soft and flabby, with a capacious bran- 

 chial cavity ; anterior dorsal edge advancing somewhat in the middle 

 and directly united to the head, so as to leave no free edge medially, by 

 a rather wide commissural band, the sides of which diverge as they 

 extend backward within the mantle. Caudal fin long, narrow, lanceo- 

 late, narrowly acuminate to a very long, acute tip ; the anterior inser- 

 tions are wide apart, and the anterior border is rounded. Head short 

 and small, exclusive of the eyes, which are very large, globular, and 

 prominent, their lower sides in contact beneath the head; openings 

 round, looking somewhat downward; pupils large and round; lids thin 

 and simple. Siphon very large and prominent, extending forward be- 

 tween the eyes, but without a special groove ; dorsal surface firmly 

 united to the head by a thick commissure, leaving about half the length 

 free ; opening large, without any valve. 



Arms comparatively small and short, none of them complete in our 

 specimen except those of the third and fourth pairs, which are nearly 

 equal in length, the ventral ones a little the shortest and most slender; 

 the dorsal and second pairs of arms have lost their distal portions, but 

 the parts of the dorsal arms remaining correspond in size with the 

 ventral ones, and those of the second pair with the third pair. The 

 arms are all united together by a thin, delicate basal web, which extends 

 up some distance between the arms (farthest between the dorsal pair), 

 and then runs along the sides of the arms, as broad, thin marginal 

 membranes, to the tips. Suckers of the vential arms smaller and dif- 

 ferent in form from those of the others, all of them being urceolate, with 

 narrow apertures, surrounded by a slightly enlarged border, and having 

 small horny rings, with the edge entire, or nearly so, on the proximal 

 suckers, but on the smaller ones, toward the tip, with a few broad, blunt 

 teeth on the outer edge. On the dorsal and lateral arms the basal suck- 

 ers are veutricose and urceolate, like those of the ventral arms, but along 

 the middle portion of these arms the suckers become much larger, and 

 have a broad, shallow form, with wide apertures and expanded bases ; the 

 horny rings of these larger suckers are divided into several broad, bluntly 

 rounded teeth on the outer edge ; toward the tips of the arms the smaller 

 suckers again become deeper, with more contracted apertures, and with 

 a few more prominent denticles on the rings. 



Outer buccal membrane with seven obtuse angles, and united to the 

 arms by seven bridles, or commissures, of which the upper one is double. 

 Exposed part of the beak black; mandibles very acute, strongly in- 

 curved. 



Pen very thin and narrow, and of nearly uniform width (4 mm ) for more 

 than half its length ; at about four-sevenths of its length from the 

 anterior end it gradually expands laterally into a broad, very thin, lan- 

 ceolate form, becoming, opposite the broadest part of the fin, 30 mm wide, 

 with very delicate lateral expansions and with a pretty strong dorsal 

 keel; farther back it tapers and is very acuminate, the lateral margins 

 S. Miss. 59 22 



