WOLFF: BEAK KEY FOR EIOHT OEPHALOPOD SPECIES 



OUTER 



hood 



POSTERIOR 



INNER 



(c) 



rostrum 



rostrum 



jaw angle 

 — shoulder 



wing base ANTERIOR jaw angle 

 insertion 



anterior margi 

 ( produced) 



Figure 2.— Descriptive characteristics of the upper and lower beak; (a) deeply recessed jaw angle, (b) moderately recessed jaw 

 angle, (c) jaw angle not recessed, (d) pigment stripes on inner surface of rostrum and crest, (e) hood deeply notched at crest, (f ) hood 

 slightly notched at crest, (g) upper beak characteristics, (h) lower beak characteristics. 



la. 

 lb. 



2a. 



2b. 



KEY TO THE UPPER BEAK 



*Alternate beak ratio 

 **Alternate beak ratio CI greater than the difference between the species means. 



Jaw angle deeply recessed 



Jaw angle not deeply recessed 



Prominent groove at jaw angle 



Groove absent at jaw angle 



6 

 2 



3 

 4 



361 



