![Picture](/uploads/2/3/7/3/23735607/2930173.gif)
Arms and web
Suckers in males not greatly enlarged, not in two fields.
Sucker aperatures without tooth-like structures
Cirrus length comparable to 2.5 times largest sucker diameter.
Single web nodules present (arrow).
Head: Eyes: Large, diameter typically 1/3 of head width.
Pigmentation: No areolar spots
Fins: Length approximately equals mantle width.
Gills: Semi-sepioid (in G. innominata) or half-orange appearance.
Pigmentation: No areolar spots
Fins: Length approximately equals mantle width.
Gills: Semi-sepioid (in G. innominata) or half-orange appearance.
![Picture](/uploads/2/3/7/3/23735607/2365130.jpg?289)
Digestive system
Intestine approximately equal to esophagus (including crop) in length.
Digestive tract arranged in simple U-shape.
Digestive gland unilobular.
Radula present or absent.
![Picture](/uploads/2/3/7/3/23735607/9041088.gif)
Optic lobe and optic nerve bundles
Optic lobe circular (rather than kidney-shaped) in cross-section.
Single nerve bundle from optic lobe penetrates white body.
![Picture](/uploads/2/3/7/3/23735607/6749034.gif)
Shell
U-shaped, lateral walls of wings usually parallel to one another. Mid-saddle
often with outer and inner surfaces convex but outer surface flat or concave in
some species
Shoulders with or without shoulder blades.