BY JAMES C. COX, M.D., F.L.S., ETC. 779 



Family I. OCTOPODID^E. 



Synopsis of Genera. 

 a. Arms with three rows of suckers. 



* Body not finned. 



Genus Tritaxeopus, Owen, T.L.S., London, pt. 5, Vol. xi., 1881. 



Body oval, rounded : arms long: suckers sessile. 



b. Arms with two rows of suckers. 



Genus Octopus, Cuvier. 



Body oval, rounded. Arms long: suckers sessile. 1st or 

 3rd right arm of male hectocotylized. 



Genus Cistopus, Gray. 



Similar to Octopus, but with a small aquiferous pore upon each 

 web between the arms. 



Genus Scjeurgus, Troschel. 



Body oval : arms short : cups with narrowed bases : third left 

 arm hectocotylized. 



** Body finned. 

 Genus Pinnoctopus, D'Orbigny. 

 Body orbicular : arms long. 



c. Arms with a single row of suckers. 

 * Not finned. 

 Genus Eledone, Leach. 

 Body rounded ; third right arm hectocotylized. 



Genus Bolit.exa, Steenstrup. 

 More gelatinous than Eledone : suckers smaller, less developed. 



** Finned. 



