1881.] THE SURVEY OF H. M.S. 'ALERT.' 25 



greater in L. gahi, and their form, judging from the figure of them, 

 more acute. 



The form and attachment of the fins to the back are very similar 

 in L. brasiliensis and L. patagonica. The former, however, is a 

 broader species, has a diiferently shaped shell, and several other 

 differences. 



Onychoteuthis ingens, sp. n. (Plate III. figs. 1-1 d.) 



Sab. Port Riofrio, west coast of Patagonia. 



The head only of a species of this genus was sent by Dr. Cop- 

 pinger. It differs in certain particulars from the known species, and 

 is especially interesting on account of its great size. 



Description. Of the arms, the upper or dorsal pair are most 

 slender and the shortest, the two lateral pairs about equal in thick- 

 ness, the upper pair having a slight advantage in length, in this 

 respect agreeing with the lower or ventral pair, which, however, are 

 a trifle broader at the base than any. The latter arms have a re- 

 markably broad and almost flat outer surface, and are roundly angled 

 at the margins ; the sides are flattened and converge, so tliat the 

 inncrside, likewise flat, becomes but little broader than half the out- 

 side ; the outer margin is provided with a broad membranous ex- 

 pansion, which apparently extends to the extremity of the arm : it 

 is widest at the base, where it connects the adjoining arm, gradually 

 narrowing towards the tip. Lower lateral pair also furnished with a 

 membrane on the upperside, which, however, is very much the broad- 

 est near the middle of the arm. The upper lateral pair are provided 

 with a membrane on the lower side ; but it is very narrow ; and the 

 dorsal pair are destitute of any. The suckers are arranged in two 

 alternating series, commencing a short distance (about an inch) from 

 the base of the arms. They are subspherical, shortly pedunculated, 

 provided with simple-edged horny rings, largest towards the middle 

 of the arms and gradually diminishing towards the tip, those upon 

 the ventral pair being a trifle smaller than those upon the other arms, 

 and the largest upon the lower lateral pair. 



Tentacular arms are in length with respect to the sessile arms as 

 5 to 3. They are eompressedly rounded, thickish, equalling in the 

 greatest diameter the basal arms ; they narrow very gradually towards 

 the extremity, with the terminal club scarcely at all widened and 

 occupying just one fifth of the entire length of the arm. Along one 

 side from the base to the end runs a very small membrane. The 

 extremity of the club is much compressed. The hooks are in two 

 alternating series of fourteen each, those of one row being decidedly 

 larger than those of the other, especially the fifth to the tenth hooks, 

 which are very formidable. The cups of the carpal group are ten in 

 number, with about eleven interjacent tubercles, the whole occupying 

 a surface of an elongate-oval form. The cups of the terminal group 

 are thirteen or fourteen in number, and contiguous to one another, 

 and all open, with horny rings. 



The horny mandibles are black, the upper one considerably the 

 longer, narrower, and more hooked. 



