CATALOGUE OF CEPHALOPODA. 



Fam. I. OCTOPID^. 



Body united to the head in front by a medial fleshy band. 



Head without any aquiferous opening. Arms conical, tapering, 



with short sessile cups. No external nor internal medial shell. 



Living near the shores amongst rocks. 



Acochlides Latr. Fam. Nat. 168. 1828. 



Octopidse D'Orh. Moll. Viv. et Fos. i. 159. 164. 1845. 



Octopodina Gray, Proc. Zool. Sgc. 1847, 205. 



Synopsis of the Genera. 



1. Octopus. Arms with two rows of cups. Body round, without 



fins. No aquiferous Cells between the bases of the. arms. 



2. CiSTOPUS. Arms with two rows of cups. Body round, without 



fins. Distinct aquiferous Cells between the bases of the arms. 



3. PiNNOTOPUS. Arms with two rows of cups. Body with fins. 



4. Elebone. Arms with one row of cups ; without beards, and 



united by a short web. Body round. 



5. Cirroteuthis. Arms with one row of cups, bearded, and 



united by a broad web. Body finned. 



A. Arms with two Rows of Cups. 



1. OCTOPUS. 



Body small, round, without any lateral fins, often cirrose. Cirri 

 often nearly disappearing in repose, and when preserved in 

 spirits. — Head with, two small internal cartilages, one on each 

 side of the beak ; in the direction of the body (not oblique), 

 narrower than the body. Eyes small, lateral, covered by the 

 continuation of the surrounding skin, and often by one or two 

 transparent eyelids. Beak very much compressed. External 

 ear slightly marked above the cervical band. No aquiferous 

 cells between the bases of the arms. — Arms unequal, elongate, 

 united at the base by a web, which is wider beneath. Cups 

 sessile, two-rowed, flat. — Siphuncle elongate, conical, slender, 

 without any superior bands, or valve. — Living on rocks on the 

 coast, very agile, eating Crustacea, and changing their colour 

 rapidly. Egg transparent, in bunches attached to Algce. 



UoXi'TTovQ Aristoteles. 



Polypus Plinius, Belon, Rodeletius. 



