492 The Molluscan Family Planorhidae 



PLATE 128 



Shells of Planorbidac 



1.2. Drcpanotrema cultratum panuco Pilsbry. Tampico, Mexico. B1183. 



3-5. Drepanotrema cultratum panuco Pilsbry. Pasture west of San Dieguito, San Luis 



Potosi Co., Mexico. Locotypes. B2124. 

 6. Drcpanotrema cultratum labrosum Pilsbry. Brownsville, Texas. U.S.N. M., 273933. 

 7-10. Drepanotrema cultratum labrosum Pilsbry. Brownsville, Texas. Locotypes. 



B1192. 

 11-16. Drepanotrema sumichrasti (Crosse and Fischer). Barbovu' Lathrop Trail, Barro 



Colorado Island, Gatun Lake, Canal Zone. B3967. 

 17-19. Drepanotrema cimex (Moricand). Brazil. U.S.N.M., 121018. 

 20-22. Drepanotrona cimex (Moricand). Anapolis, Guyoz, Brazil. M.C.Z., 65716. 

 23-25. Drepanotrema peninsularis (Cooper). {^Drepanotrema anathuon) . Santa 



Anita, Lower California. U.S.N.M., 129291. 

 26-30. Tropicorbis obstructns (Morelet). Tampico, Mexico. U.L, Z28550. 

 31-33. Tropicorbis obstructns (Morelet). Lake Amatitlan, Guatemala. B2125. 



Figures 1 to 30 are enlarged about five diameters; figs. 31 to 33 

 are enlarged about four diameters. 



