panamic-pacific pelecypoda sss 



Explanation of Plate 82 



Figure Page 



1-lb. Periploma (Periploma) alta (C. B. Adams) 461 



Figs. 1, la, interior and exterior of the type, height 50 mm., 

 Fig. lb, a section of surface highly magnified. Panama (C. B. 

 Adams). MCZ. 



2-2e. Periploma (Periploma) planiuscula Sowerby 463 



Fig. 2, length 54.2 mm., Guanico, Panama. PRI 25942A; Fig. 2A, 

 length 51.2 mm.; Fig. 2b, length 53.2 mm., Tumbez, Peru. PRI 

 25942B; Fig. 2d, a section of the surface highly magnified. Sua, 

 Ecuador.; Fig. 2e, a section of the surface highly magnified. 

 Huntington Beach, California. 



3-3a. Periploma (Albimaniis) pentadactylus Pilsbry and Olsson 464 



Length 21.3 mm. Guanico, Panama. PRI 25943. 



4. Periploma (Periploma) discus Steams 461 



Figure after Stearns, 1890, length 41 mm. San Pedro, California. 



5-5b. Periploma (Periploma) lagartilla, new species 463 



Length 23 mm. El Lagartillo, Panama. Holotype, ANSP 218951. 



6. Periploma (Periploma) steamsli Dall 462 



Exterior of a right valve, length 46 mm. Gulf of California. Holo- 

 type, USNM 110548. 



7-7a. Periploma (Periploma) carpenteri Dall 462 



Length 47 mm. Gulf of Panama. Holotype, USNM 106891. 



