Manchester Memoirs, Vol. xlviii. (1904), No. %\. 5 



(Suckers in two rows Alloposus. 

 Suckers in a single row Bohtaena. 



/Mantle connection consisting of either deep grooves 

 and ridge, or cartilaginous knobs on the mantle and 

 corresponding hollows at the base of the funnel ; 

 aquiferous pores present ; hectocotylus involving the 

 whole arm, which is separable. (ARGONAUXiDiE)... 10 



Mantle connection consisting of shallow folds on hinder 

 margin of funnel and shallow groove on the mantle ; 

 no aquiferous pores ; hectocotylus confined to tip 

 \ of arm, never free. (Polypodid^) 13 



'Funnel organ made up of three separate portions ; 

 mantle connection cartilaginous ; an aquiferous 

 pore at either side of the siphon, none in the head. 1 1 



10.^ Funnel organ composed of numerous longitudinal 

 lamellae ; mantle connection composed of mem- 

 branous folds, without cartilage ; an aquiferous pore 

 at either side of the siphon and two in the head ; 

 hectocotylised arm on the right side Tremoctopus. 



Body 10 cm. or more in length ; with tubercles con- 

 nected by ridges on the ventral aspect Ocytho'e $ 



Body 30 mm. or less in length, with one ventro-lateral 

 arm developed in an oval sac and specially modified 

 into a separable hectocotylus 12 



THectocotylus on the left side Argonauta $ 



[Hectocotylus on the right side Ocytho'e $ 



n- 



'Suckers on the arms in a single row 14 



Suckers on the arms in two rows 17 



Suckers on the arms in three rows Tritaxeopus.^ 



