508 CEPHALOPODA. 



Class CEPHALOPODA.* 



Head large, separate from the body ; eyes large, complex, lateral ; 

 ears developed ; mouth armed with two horny or shelly jaws edged 

 with fleshy lips, surrounded by eight or ten fleshy arms, and fur- 

 nished with an entire or slit tul)e or siphuncle used in locomotion. 

 Body ovate, roundish, or cylindrical, open in front, containing the 

 viscera and one or two pairs of internal symmetrical gills ; naked ; 

 surrounded by a thin shell with a single cavity ; or partly or entirely 

 contained in the last chamber of a chambered shell furnished with 

 a siphon passing from chamber to chamber. Individual uni-sexual. 

 Animal free, walking on its head, or swimming in the sea, propelled 

 by the water from the siphon tube. 



Order DECAPODA. 

 Body naked. Head separate, with ten fleshy arms, the two longer 

 arms furnished with peduncled cups with a horny circle ; eyes free 

 in the orbit. Siphuncle entire ; gills two. Foot none. An inter- 

 nal medial shell. 



Family LOLIGOPSIDtE. 



Eyes naked. Mantle supported by two internal fleshy bands. 

 Siphuncle simple. 

 Shell solid, horny. 



The members of this family have the eyes peduncled and not cov- 

 ered by a skin ; the fins are caudal, terminal, and semi-circular ; 

 the body is memln-anaceous, semi-pellucid, elongate, and tailoring 

 behind. They inhabit the high seas and are powerful swimmers. 



* I am responsible for all that relates to the Cephihpods. Dr. Gould had prepared 

 nothing on this class. The descriptions of families, &c. are copied from H. and A. 

 Adams. — W. G. B. 



