WOLFF: BEAK KEY FOR EIGHT CEPHALOI'OD SPECIES 



Figure 10.— The upper (see bottom of p. 366) and lower beak of 

 Sympleetoteuthis oualaniensis (1 - ML = 130 mm, URL = 0.35 

 cm, LRL = 0.33 cm; 2 - ML = 188 mm, URL = 0.55 cm, LRL = 

 0.50 cm; 3 - ML = 290 mm, URL = 0.76 cm, LRL = 0.70 cm). 



KEY TO THE LOWER BEAK 



la. 

 lb. 



2a. 



2b. 



3a. 

 3b. 



4a. 



4b. 

 5a. 



5b. 



Ridge or fold on lateral wall 



Ridge or fold absent on lateral wall. 



2 

 3 



RL/JW M.173 (CIos = 1.308+0.059); *RC/RL <3.091 (CI 05 = 2.96+0.122) 



Abraliopsis affinis 



Jaw angle not recessed; no hood notch at crest; anterior-posterior ridge or fold on lateral 



wall 4 (Fig. 2); pigment changes with growth shown in Figure 4. 

 RL/JW <1.173 (CIos = 1.037+0.059); *RC/RL >3.091 (CIos = 3.222+0.122) 



Onychoteuthis banksii 



Jaw angle not recessed; no hood notch at crest; prominent anterior-posterior ridge on 



lateral wall (Fig. 2); pigment changes with growth shown in Figure 3. 



Jaw angle strongly recessed 



Jaw angle slightly or not recessed 



6 



4 



RL/JW M.134 (CIos = 1.235+0.059); *RW/JW >3.565 (CIos = 3.87+0.157) 



Liocranchia reinhardti 



Jaw angle slightly recessed; no hood notch at crest; pigment changes with growth shown 



in Figure 6. 

 RL/JW <1.134 (CIos = 1.032+0.059) 5 



RC/RL >3.741 (CIos = 4.058+0.122); *RL/WL <0.418 (CIos = 0.380+0.033) 



Loligo opalescens 



Jaw angle not recessed; no hood notch at crest; anterior margin of lower wing often pro- 

 duced; pigment changes with growth shown in Figure 7. 



RC/RL <3.741 (CIos = 3.424+0.122); *RL/WL >0.418 (CIos = 0.457+0.033) 



Pterygioteuthis giardi 



Jaw angle not recessed; no hood notch at crest; pigment changes with growth shown 

 in Figure 5. 



4 A ridge or fold on the lateral wall of the lower beak is characteristic in many cephalopod species (e.g., Histioteuthis spp.). 



367 



