12 HOYLE, Genera of Recent Dibranchiate Cephalopoda. 



/Luminous organs, few in number (not exceeding 20), 

 - ^ ^ comparatively large and tubercle-like 54 



vLuminous organs numerous and small 55 



'Luminous organs, about 9 on each side the mantle, 

 leaving the median portion free ; also on the stem 

 of the tentacle, body rounded behind ...Thelidioteuthis}^ 



Luminous organs m the median Ime of the mantle ; fin 

 reaching to the anterior margin of the mantle and 

 nearly to the posterior Ancistrochirus. 



'Luminous organs in seven rows down the ventral 

 surface of the mantle ; arms with only hooks ; 

 tentacle-club with two rows of fairly numerous 

 hooks Enoploteuthis, 



55- 1 Luminous organs numerous and scattered all over the 

 ventral surface ; and a few on the dorsal surface ; 

 arms with suckers at the tips ; a single row of few 

 hooks on the tentacular club and two rows of 

 suckers Abralia. 



Tunnel articulating with the inner surface of the mantle 



by a cartilaginous joint on either side 57 



56. 



57-1 



Funnel fused with the inner surface of the mantle on 

 either side 75 



Animals of gigantic size, mantle 2 to 3 metres in length ; 

 tentacle with a fixing apparatus consisting of 

 alternating pads and suckers extending along the 

 stem ; pen feather-shaped with a terminal cone ; 

 siphonal articulation unknown. 



(Architeuthid^) Architeuthus. 



Animal of moderate size ; mantle length not exceeding 

 0*7 metre; generally much less 58 



