OCTOPIA. 



Cephalopoda dibranchia Owen, Trans. Zool. Soc. ii. 103. 1838. 

 C. dibranchiata Gray, Proc. Zool. Soc. 1847, 204. 

 Antliobrachiaphora, Anosteophora, et Sepiaphora Gray, Lond. 



Med. Rep. 1821. 

 C. antepedia Rajiu. Anal. Nat. 139. 1815. 



Okder I. OCTOPIA, 



Body short, rounded, united to the head by a broad cervical band. 



Sometimes ? covered with a thin single-chambered shell. 

 Head very large, with aquiferous opening; none on the gills or 



lips. Siphuncle without any internal valve. Eyes fixed, united 



to the skins, incapable of rotation. Buccal membrane none. 

 Arms eight, all sessile, without swimming membranes. Cups 



sessile, flat, and without any horny ring. Tentacular arms none. 

 No internal medial dorsal shell. 

 The front of the mantle is supported by a fleshy band or by fleshy 



buttons on the siphon (apparatus of resistance, D'Orb.), fitting 



into grooves on the inner side of the mantle. 



Cephalopoda octopoda Leach, Zool. Misc. iii. 1817; Ferussac, 



Tab. Syst. 18. 1821 ; Gray, Proc. Zool. Soc. 1847, 204.; Latr. 



Fam. Nat. 167. 1828. 

 Antliobrachiaphora, Anosteophora, Gray, Lond. Med. Rep. 1821. 

 Cryptodibranchiata octocera Blainv. Diet. Sci. Nat. xxxii. 1824; 



Menke, Syn. ed. 2. 1830. 

 Cephalopoda octopodre Menke, Syn. 1. 1828. 

 C. octopoda Gravenliorst, Thier. 1845. 

 Octopodida? Gray, Proc. Zool. Soc. 1847, 204. ; Cantr. Malac. 



Medit. 13. 1841. 

 C. octopia and argonautea Rajin, Anal. Nat. 140. 1815. 

 C. octobrachides Blainv. 

 C. oetoceres Blainv. 



Synopsis of Families. 



I. Octopidje. Arms subulate. Mantle supported by fleshy 

 bands. No cephalic aquiferous apertures. 



II. Philonexidje. Arms subulate. Mantle supported by two 

 buttons at the base of the siphuncle, fitting into grooves on 

 the mantle. 



III. Ocythoid.e. Arms subulate, two upper palmate. Mantle 

 supported by two buttons fitting into grooves on the base 

 of the siphuncle. 



B 2 



