208 BULLETIN U2, UNITED STATES NATIONAL MUSEUM. 
Page. 
Scissurella 
Searlesia 
Seguenzia 141 
Seila 144 
Seniele 48 
SemiMttium 146 
Septifer 21 
Serridens 37 
Serripes 40 
Siliqua 50 
Simnia 139 
Simrni 165 
Siphonaria 66 
Siphonodentalium 58 
Skeneopsis 158 
Solaricida 177 
Solariella 177 
Solemya : 9 
Solen 50 
Sphenia 53 
Spiratella 58 
Spiroglyphus 151 
Spisula.. : 51 
Spongioradsia 189 
Sport ella 88 
Stenoplax 190 
Stenoradsia 190 
Strigatella 86 
Strioterehrum 67 
Strioturhonilla : 121 
Stromhiformis 119 
Stylidium 145 
Styliola 59 
Suavodrillia 69 
Sulcosinus 92 
Sulcosipho-- 96 
Sulcularia 61 
Sveltia 84 
Symmetrogephyrus 198 
Synimorphomactra 52 
Syncera 161 
Tachyrliynchus 152 
Tagelus 50 
Taranis 83 
Tegula 174 
Teinostoma : 182 
TelUna 45 
Terebra 67 
Teredo 56 
Tethys 65 
Thais 111 
Thala 87 
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Thracia 25 
Thyasira^^ 33 
Thylacodes 151 
Tindaria 15 
TAvela 41 
Tonicella 188 
Tonicia 195 
TorelUa 167 
Tr achy car dium 39 
Transennella 41 
Trichotropis 148 
Tricolia 171 
Tridonta 30 
Trifora 142 
Trigoniocardia 39 
Tripoplax 193 
Triremis 106 
Tritonalia. : 107 
Trivia 140 
Trophon 109 
Trophonopsis 111 
Truncatella 160 
Turbonilla 120 
Turcica 177 
Turcicula 177 
Turritella 151 
Turritellopsis 152 
Turtonia 38 
Tylodina 65 
Urosalpinx 109 
Velutina 167 
Verier ella 42 
Venericardia 31 
Verier upis 44 
Ventrieola 41 
Venus 42 
V ermicularia 150 
Vermiculum 151 
Verticordia 29 
Vesicomya 40 
Vitrinella 18I 
Volutharpa 102 
Volutomitra 87 
Volutopsius 89 
Volvulella 62 
WilUamm 67 
Xiphiozona 187 
Xylophaga 56 
Yoldia 13 
Yoldiella 1 4 
Zeuxis 103 
Zirfaea 55 
