[71] CEPHALOPODS OF NORTHEASTERN COAST OF AMERICA. 281 



ties iu the armature, both of the sessile and tentacular arms, as given 

 above (p. 70), are quite sufficient, however, to warrant its separation 

 from all the other genera. Its pen, as figured, also differs from all others 

 hitherto described. It is narrowest anteriorly, gradually and slightly 

 expanding backward to the one-sided, conical hood or cone, which is not 

 inserted into a solid terminal cone, as in Moroteuthis robusta, and the 

 blade is relatively larger. The caudal fin is large, rhomboidal, and 

 acute posteriorly, as in the latter. The tentacular club bears two large, 

 abruptly curved, claw-like hooks in the middle, with numerous small 

 suckers around them and on the proximal part. The length of the head 

 and body of the original example was about 28 cm (11 inches). 



This genus is, in the character of its armature, very much like Gonatus 

 Sars; the structure of its pen appears to be similar. 



Mr. Dall has described a small species (probably young) from the coast 

 of California, which may possibly belong to the same group. He re- 

 ferred it doubtfully to Onychoteuihis (0. lobipennis Dall). 



A large Cephalopod, referred doubtfully to Ommastrephcs, has been re- 

 corded from Japan and described by Dr. F. Hilgendorf.* It was taken 

 on the east coast of Japan, north latitude 35° to 36°. It had been split 

 open, salted, and partly dried, and the viscera had been removed. The 

 ends or clubs of the tentacles were also gone. Iu this condition it was 

 on exhibition iu Yeddo. The following are the measurements given: Tip 

 of tail to front edge of mantle, 1SG"" (G feet, 1 inch); mantle to mouth, 

 about 41 cm (1 foot, 5 inches); longer sessile arms, 197' m (6.5 feet); from 

 tip of tail to tip of sessile arms, 414 om ; total expanse across outstretched 

 tentacles, G00 cm ; circumference of mantle (breadth as cut open), 130 cm ; 

 length of caudal fin, 60 cm ;- breadth of caudal fin in middle, 45 ,m ; breadth 

 of forward end of caudal fin, 2S rm ; diameter of posterior tip, 1""; tongue 

 of funnel, 10 cm broad, G"" long; eye-opening, which was oblong-oval, 

 without an obvious sinus, 19 ,m ; distance between eyes, 2G""; diameter of 

 oval skin of lip, 12 cm by 8 m ; breadth of sessile arms, ll cm ; of tentacles, 

 2 cm to 3 cm ; diameter of horny rings of suckers on base, 1.5 cm ; height, 

 0.7 mm ; number of denticles, 37. 



The great size, and especially the length, of the caudal fin in propor- 

 tion to that of the mantle ,(£) render it probable that this was not a spe- 

 cies of Architeutliis. The form of the fin, its length^xceeding its breadth, 

 is unlike the usual proportions in Ommastrephes and Sthenoteuthis. It 

 is more probable that this specimen belonged to Moroteuthis robusta, or 

 to some related form not yet characterized. 



D. — Note on large species of Octopus. 



Although this article relates specially to the gigantic species of ten- 

 armed Cephalopods, it may not be amiss to add a few lines in respect to 

 species of Octopus that attain large dimensions. It is certain, however, 



*Mittheilungen der deutschen Gesellschaft fur Natur uud Viilkerkunde Ostasiens. 

 Heransgegeben von dom Vorstande, 1st Heft, p. 21, May, 1873, Yokohama, Japan. 

 See also American Journal of Science, vi, p. 237, September, 1873. 



