44 BELOSEPIID^. 



they serve for the seizure of food. I have been able to verify 

 this fact a second time in examining the Calamaries — which pur- 

 sued a troupe of little fishes, capturing them with these members. 

 Moderate forward or backward progression is not due solely to 

 the fins, but is assisted by the expulsion of water from the funnel ; 

 if the animal move forward, the funnel is recurved in front, and 

 forms nearly a right-angle with the body ; in retrograde move- 

 ment the siphon becomes horizontal ; it is placed to the right or 

 left when the Sepia would turn, and is strongl}?- recurved from 

 front to back when it would mount to the surface of the water. 



The variations of form of the siphon are indisputable, and one 

 cannot doubt their influence upon the direction taken by the 

 animal, but the marginal fins are not less useful ; their undulations 

 commencing anteriorly when the animal moves forward, and 

 posteriorly in backward movement ; they change suddenly as 

 the direction may be varied. The same facts were remarked 

 with regard to the Calamary. 



SEPiELLA, Gray, 1849. Cuttle-bone weaker, subcartilaginous, 

 always without either carina or posterior beak. At the posterior 

 part of the bone is a profound subcutaneous pouch, opening by 

 a large pore at the posterior extremity of the mantle between 

 the fins. 



Hemisepius, Steenstrup, 18*75. 



JDistr. — H. typicus^ Steenst. (xxvii, 46, 47). Cape of Good 

 Hope. 



Differs from Sepia by the sessile arms having only two rows 

 of suckers ; the ventral surface of the mantle with aqueous pores 

 situated in little nipples, and connected together by a longitu- 

 dinal groove. The very rudimentary calcareous partitions of 

 the inner side of the cuttle-bone only cover a portion of the 

 excessively thin plate. 



Trachyteuthis, Meyer, 1846. 



Syn. — Cocoteuthis, Owen, 1855. Glyphiteuthis, Reuss ? 



Distr. — 3 fossil species from the Jurassic of Europe. T. hasti- 

 formis, Ruppell (xxviii, 71). 



Shell like Belosepia, thickened ventrally by horny, instead of 

 chalky layers. 



The shell resembles Sepia in the dorsal side being granulated, 

 but the ventral side is horny instead of chalky; the posterior 

 end has long wing-like expansions. 



Family BELOSEPIIDJE. 



Belosepia, Voltz, 1830. 

 Distr. — 5 fossil species. European Eocene. B. sepioidea^ 

 Blainv. (xxviii, 64, 65). 



