MOLLUSCS. 375 



thick body, rounded behind, the eyes with a lower and sometimes an upper lid, the 

 tentacles more or less completely retractile, and the arms furnished with two rows of 

 acetabula. The fins are separate, and attached near the middle of the body. This 

 family is represented on our coasts by the genera Sepiola, Eossia, and Heteroteuthis, 

 the species of which are far from common. 



The species of Cranchia, the only genus of the fq,mily Ceanchiid^, have a short, 

 round body, with two small fins on the hinder end a small head, with large eyes, the 

 cornea of which is perforated so that the searwater penetrates to the lens, two rows of 

 suckers on the arms, the tentacles long and armed with eight rows of acetabula. 

 Closely allied is the family DESMOTEUTHiciB, with its two genera, Desmoteuthis and 

 Taonius, in which the body is longer and pointed posteriorly. 



In the LoligopsidjE the form is longer and the fins are large, the head very small, 

 the arms with two rows of suckers, the tentacles not retractile, the siphon without 

 valves. Of Histioteuthis three species are known, two of which are found in the 

 Mediterranean, while of the third, H. coUinsii, found off Nova Scotia, one imperfect 

 specimen and the beaks of two others are all that have been found. The other pro- 

 minent genera are Loligopsis, Mastigoteuthis, Chiroteuthis, and Thysanoteuthis. 



In the family Teuthid^ the tentacular arms are 'distally armed with sharp, horny 

 and recurved hooks, which, to a greater or less extent replace the sucking discs, and in 

 some of the genera the other arms bear hooks as well as suckers, while others have hooks 

 alone. The tentacular arms, which are used, as in all decacerous cephalopods, for the 

 capture of the prey, can be fastened together by the sucking discs for a greater or less 

 proportion of their length, leaving the extremities to form a living forceps, from which 

 escape is next to impossible. The eyes are provided with lids, and the cornea is per- 

 forated as in the last family. 



Possibly to be placed here is the large species Moroteuthis robusta, found by Mr. 

 Dall in Alaska. Three mutilated specimens were seen, the largest of which, when 

 found, had a total length of fourteen feet, but the terminal portions of the tentacular 

 arms were gone, and so the actual size was somewhat greater. The length of the man- 

 tle was seven feet seven and a half inches, and the diameter of the body eighteen inches. 

 A peculiarity exists in the pen, the posterior end of which "is one-sided, funnel* 

 shaped close to the tip," and " inserted intg a long, round, thick, firm, cartilaginous 

 cone, which tapers to a point posteriorly," which thus, as pointed out by Professor 

 Verrill, corresponds to the guard of the extinct Belemnites, both in position and in its 

 relation to the pen. Nothing like this is known in any other recent genus. 



Among the undoubted members of the family may be mentioned the genus Ony- 

 choteuthis, in which the forceps of the tentacular arms is well developed. The club 

 which terminates each of these arms bears on its inner surface two rows of recurved 

 hooks, while just below are a number of suckers which serve to unite the two arms. 

 The sessile arms have suckers only. 0. banksii, one of the ten known species, ranges 

 from the Arctic seas to the Cape of Good Hope and the Indian Ocean. It is'solita«-y 

 in its habits, frequenting the open seas, and is most numerous round the banks of gulf 

 weed. In Mioploteuthis and three or four other genera, all the sessile arms bear 

 hooks but no suckers, the tentacular arms being much as in the last genus. 



The last family to be mentioned is the Ommasteephid^, in which the body is 

 long and tapers to a point behind ; the arras are short and without hooks, but fur- 

 nished with two rows of suckers ; the tentacular arms are not retractile, but terminate 

 in an expanded club, armed with four rows of suckers. The eyes are provided with' 



