COMPLETE GRAU : PECTINIDAE OF THE EASTERN PACIFIC 23 



3. Entire surface sculptured 



4. Concentric sculpture stronger than radial 



5. Fine concentric lamellae and microscopic radial 



striae bistriatus (Dall) 



(southern California; Lower California) 



5. Prominent concentric lamellae and finer radial 



ridges barbarensis sp. nov. 



(southern California) 



4. Concentric and radial sculpture of approximately equal 

 strength 



6. Very faint striae; umbonal folds sharply angled 



subhyalinus (E. A. Smith) 



(off southern Chile) 



6. Fine lamellae ; concentric more apparent when shell 

 viewed in upright position, radial more so when 

 viewed from anterior or posterior margin . . 



liriope (Dall) 



(Gulf of Panama; Galapagos Islands) 

 3. Sculpture on only upper 3^ to ^ of disk; minute con- 

 centric and radial ridges; disk extremely thin and often 

 with several faint concentric folds . zephyrus sp. nov. 

 (southern California) 

 1. Shell thicker and opaque; right valve concentrically ridged 

 7. Left valve with only radial ridges . pernomus (Hertlein) 

 (Cedros L, Lower California, and Gulf of California, to 

 Ecuador) 

 7. Left valve with only concentric ridges; ridges minute 



acutus sp. nov. 



(western Colombia) 

 7. Left valve with concentric lamellae and radial ridges 



8. Hinge line short; anterior auricle of right valve with 5 



radial ridges incongruus (Dall) 



(northwest of Cedros L, Lower California) 

 8. Hinge line nearly as long as disk; anterior auricle of 



right valve with 10-12 radial ridges 



exquisitus sp. nov. 



(Galapagos Islands; Peru to northern Gulf of California) 



