Sphzrium fabale, 115, 778, 119. 
lilycashense, 795, 396. 
occidentale, 113, zzg, 124. 
simile, 113, 776. 
solidulum, 7z3, 115, 117. 
stamineum, 1138, zzz, 116, 
117, 118, 395. 
Striatinum, 112, 113, 114, 
ri. 
vermontanum, 394, 395. 
Spirogyra, 298, 299, 
Statistics, 33. 
STENOTREMA, 140, 763. 
STREPTODONTA, 770. 
STREPTONEURA, 7/9. 
Strobila, 225. 
Strobila morsei, 225. 
strebeli, 225. 
STROBILOPS, 225, 228. 
Strobilops labyrinthica, 225, 226. 
STROPHITUS, 66. 
Strophitus edentulus, 65, 67, 6°, 73. 
pavonius, 65, 68, 69. 
STYLOMMATOPHORA, 739. 
SUCCINEA, 277, 218, 
Succinea alba, 223. 
avara, 223, 224. 
calumetensts, 220. 
compacta, 223. 
decampi, 220. 
Sorshey?z, 220, 
magister, 223. 
major, 225. 
obligua, 218, 220. 
ovalis, 217, 275, 219, 220, 224. 
pellucida, 260. 
peoriensis, 220. 
retusa, 220, 222, 224, 260. 
totteniana, 278, 220. 
vermeta, 223 
waradtana, 223. 
wzlsont, 220. 
SUCCINID, 2/6. 
SYMPHYNOTA, 392. 
Symphynota complanata, 392, 
compressa, 58, 392, 
costata, 392. 
TA£NIOGLOSSA, 379. 
Tebennophorus, 200. 
TELEODESMACEA, ///. 
Tellina pusilla, 127. 
TESTACELLA, 769, 170. 
Testacella haliotoidea, 769, 170. 
TESTACELLID&, 769. 
Topography, 12. 
TrRIoDoPsIs, 140, 743. 
Triodopsts lunuda, 144. 
Unio, 48, 49, 65, 69 
Unio zsopus, 48. 
affinis, 103. 
approximus, 103, 
INDEX. 
Unio arctior, 70. 
asperatus, 86. 
asperrimus, 83. 
bullatus, 86. 
canadensis, 94, 
cardium, 94. 
carinatus, 108. 
chuntii, 76. 
cornutus, 89. 
costatus, 82. 
crassus, 108. 
delicatus, 39}. 
ailatatus, 70. 
adtstans, 103. 
dolosus, 99. 
dorfeuillianus, 86. 
ellipticus, 108. 
Jasctatus, 108. 
fiavus, 77. 
flortdensts, 100, 
Sragilis, 99. 
gibbosus, 66, 70, 83. 
gouldianus, 79. 
gouldii, 79. 
hildrethianus, 65, 77. 
hippopeus, 80. 
inflatus, 103. 
latecostatus, 82. 
leprosus, 101. 
lunulatus, 83. 
luteolus, 30, 33, 36. 
mortont, 86. 
novieboract, 105. 
occtdens, 9A. 
pernodosus, 86. 
pilsbry?, 82, 83. 
prelongus, 101. 
prasinus, 86. 
guadratus, 83. 
rariplicata, 80. 
riddelliz, 76. 
sageri, 101, 
satur, 94. 
schoolcraftensts, 86. 
schoolcraftiz, 86, 88. 
stliguoideus, 103. 
subovatus, 94, 
teres, 100. 
truncatus, 92. 
upsont, 108. 
zigzag, 91. 
UNIONID&, #7. 
Utricularia vulgaris, 299. 
VALLONIA, 248. 
Vallonia americana, 252, 
amurensis, 251. 
costata, 251, 252, 253. 
enniensis, 249. 
helvetica, 251. 
hispanica, 249, 
montana, 251. 
parvula, 252. 
