42 
1690 Sphezrium nobile Gould. 
21382 Spherium solidulum Prime. 
2688 Spherium Pilsbryanum 
1075 Spherium occidentale Prime. 
1688 Spherium primeanum Classen. 
1167 Sphezrium raymondi J. G. Cooper. 
1166 Sphzrium rhomboideum Say. 
52 Sphaerium securis 
54 Sphaerium similis 
1076 Spherium spokani Baird. 
1077 Spheerium striatinum Lamarck. 
53 Sphaerium sulcatum 
1078 Spherium sulcatum Lamarck. 
1079 Spherium tumidum Baird. 
3102 Genus Sphyradium Charpentier. 
3103 S: Hasta. Pleistocene, Kansas. 
3104 _ S: alticolum. Utah, Colo., and Wyoming. 
Synonymy:—Pupa and Pupilla alticola Ingersoll. 
3105 S: Edentulum. Europe, Asia, etc. 
1706 Sphyradium edentulum 
437 Spiroglyphus lituella Morch. 
1179 Spisula falcata Gould. 
1639 Spisula (Hemimactra) catilliformis Conr. 1867. 
1640 Spisula (Hemimactra) Hemphilli Dall. 1894. 
1641 Spisula (Hemimactra) planulata Conr. 1837. 
1642 Spisula (Hemimactra) polymyma Stm. 1860. 
1643 Variety alaskana Dall. 1894. 
1180 Spisula planulata Conrad. 
1334 Sportella californica Dall, 1889. Monterey, Cal. 
1335 Sportella stearnsii Dall, 1899. Gulf of Cal. 
370 Standella falcata Gould 
1569 Standella californica Conrad. 
472 Standella planulata Conrad. 
1080 Stenotrema germana Gould. 
516 Strombella middendorfii Dall. 
517 Strombella fragilis Dall. 
518 Strombella melonis Dall. 
2290 Strombus gracilior 
1439 Subemarginula yatesii 
1081 Succinea hawkinsii Baird. 
1082 Succinea Nuttalliana Lea. 
1924 Succinea Haydeni W. G. Binn. 
1925 Succinea Grosvenorii Lea. 
1926 Forma elongata: Kremmling, Colo. 
1927 Forma rufescens Ckll. Lee Co., Texas. 
1928 Succinea avara Say. 
1929-1933 Forms alba Ckll. (Custer Co., Colo.); wardiana Lea; 
vermeta Say; compacta Ckll.; major Binn. have been de- 
scribed. 
1934 Succinea oregonensis Gabbi. 
1935 Succinea chysis Wester]. 
19386 Variety aurelia Martens. 
1937 Succinea annexa Westerl. 
1084 Succinea lineata W. G. Binney. 
32 Succinea obliqua 
1083 Succinea oregonensis Lea. 
2262 Succinea retusa Lea. 
448 Succinea rusticana Gould. 
1085 Succinea sillimani Bland. 
1886 Succinea stretchiana Bland. 
