12 



g6 nautileus, L. — 36. 



a. obsoletus, Roberts. 



b. crista, L. 



97 albus, Mull. — 53. 



b. draparnaldi, Shepp. 



c. major, Loc. 



98 parvus, Say. — 23. 



= glaber, Jeff. 



b. compressus, Lloyd. 



99 dilatatus, Gould. — 1. 

 Subg. Gyrorbis. Agass. 



100 spirorbis, Mull. — 52. 



b. ecarinatus, Jeff. 



c. albidus, Nelson. 



d. scalariformis, N. &> T. 



101 vortex, L. — 45. 



b. compressus, Mich. 

 Subg. Tropidiscus. 



102 carinatus, Mull. — 43. 



b. disciformis, Jeff. 



c. minor, Pascal. 



d. albidus, Hudson. 



103 umbilicatus, Mull. — 48. 



= complanatus, Auctt. 



b. rhombeus, Turt. 



c. albinos, Baud. 



d. sinistrorsus, Hele. 



e. terebra, Turt. 



f. subscalaris, Baud. 



g. submarginatus, O. /. 



Subg. Spivodiscus. 



104 corneus, L. — 35. 



b. albinos, Moq. 



c. ferrugineus, Pasc. 



d. collisus, Pasc. 



e. major, PrtS£. 



f. minor, Pasc. 

 Subg. Bathyomphalus. Agass. 



105 contortus, L. — 44. 



b. albidus, Jeff. 



c. excavatus, Chll. 



d. subrufus, Loc. 



e. minor, Taylor. 



Physa, Drap. 



106 fontinalis, L. — 53. 



b. gelatina, Mull. 

 = curta, 



c. inflata, Jeff. 



d. oblonga, 



e. albina, Jeff. 



f. rufula, Loc. 



g. dextvovsa, Wilms. 



107 Dr/>. — 1. 

 Subg. Aplexa, Flem. 



108 hypnorum, L. — 32. 



b. major, Char p. 



c. decollata, Nels. 



d. cuprella, Roive. 



e. roseolabiata, Pasc. 



f. angulata, CHI. 



g. rufula, Loc. 



h. intermedia, Loc. 



Limn^ea, Lam. 



Subg. Amphipeplea, Nilss. 



109 glutinosa, Mull. — 7. 



b. mucronata, Jeff. 



c. intorta, C&/Z. 



Subg. Radix, Montf. 



no peregra, Mull.—j6. 

 b. involuta, Thomps. 



