CEPHALOPODA. ~ 177 



fectly chambered apex {mucro). Animal witli elongated ten 

 tacles, expanded at their ends. 



Sepia (Pliny), Linnseus. 



Type, S. officinalis, L. PI. I., Fig. 5. 



Synonyms, Bdosepia, Yoltz. (B. sepioidea, PI. II., Fig. 3, 

 miicro only.) Paleeoteutliis, Eoem. 



Body oblong, -svith. lateral fins as long as itself. Arms Y\-ith 

 four rows of suckers. Mantle supported by tubercles fitting into 

 sockets on the neck and funnel. Length 3 to 28 inches. 



Shell as wide and long as the body; very thick in front, 

 concave internally behind ; terminating in a prominent mucro. 

 The thickened part is composed of numerous plates, sejDarated 

 by vertical fibres, which render it very light and porous. S. 

 Orbignyana, PI. II., Fig. 2. 



The cuttle-bone was formerly employed as an antacid by 

 apothecaries; it is now only used as "j^ounce," or in casting 

 counterfeits. The bone of a Chinese species attains the length 

 of 1^ foot. (Adams.) 



The cuttle-fishes live near shore, and the mucro of their shell 

 seems intended to protect them in the frequent collisions they 

 are exposed to in swimming backwards. (D'Orbigny.) 



Distribution, 30 species. World-wide ; 2 British. 



Fossil, 10 species. Oxford clay, Solenhofen. Several species 

 have been founded on mucrones from the Eocene of London and 

 Paris. PI. II., Fig. 3. S. ungula occurs fossil in Texas. 



Spirtjlirostea, D'Orb. 



Type, S. Bellardii (D'Orb.). PI. II., Fig. 4. Miocene, 

 Tui'in. 



Shell, raucro only known; chambered internally; chambers 

 connected by a ventral siphuncle ; external spathose layer pro- 

 duced beyond the phragmocone into a long pointed beak. 



Beloptera (Blainville), Deshayes. 



Etijmology, helos, a dart, and pteron, a wing. 

 Type, B. belemnitoides, Blainville. PI. 11. , Fig. 7. 

 Shell, mucro (only known) chambered and siphuncled ; winged 

 externally. 

 Fossil, 4 species. Eocene. Paris ; Bracklesham. 



Belemis'OSIs, Edwards. 



Type, B. anomalus, Sby. species. Eocene. Highgate (unique). 



l3 



