26 CHONDROPHORA, 



the apex of the sepion, or cuttle-bone. The decapods 

 chiefly frequent the open sea, appearing periodically like 

 fishes in great shoals on the coasts and banks. 



Suborder CHONDROPHORA. 



Shell internal, solid, horny or cartilaginous, either lan- 

 ceolate, pennate with a central longitudinal dorsal ridge 

 above, and a groove beneath ; or flat, narrow, with a central 

 longitudinal solid rib, and a similar rib on each edge. The 

 apex solid, sometimes thickened, produced, and carti- 

 laginous. In the families Cranchiadce^ and Loligopsida', the 

 mantle is supported by two internal fleshy bands ; and in 

 CheiroUuthidfc, OnychoteutMd^^ and LoUgidce, it is furnished 

 with three internal cartilages, one dorsal and two ventral. 



Fam. CRANCHIAD^. 



Eyes covered with the skin. Mantle supported by two 

 internal fleshy bands. Siphuucle with a valve. 



Shell solid, horny. 



In this family the body is large and membranous, the 

 head is very small ; the eyes, which are large and promi- 

 nent, are covered with a continuous skin, with a small 

 transparent spot ; the club of the tentacular arms is finned 

 behind, and has four series of cups ; the buccal membranes 

 are large and lobed ; the fins of the body are terminal and 

 small. 



Genus CRANCHIA, Leach. 



Shell horny, as long as the body, narrow, bilanceolate, 

 and pointed at each end. 



