Menetus exacutus, Say, 71. 
Mesodon, Raf., 26. 
albolabris, Say, 26. 
bucculenta, Gould, 29. 
var. rufa, Michener, 29. 
clausa, Say, 28. 
dentifera, Binn., 30. 
Pennsylvanica, Green, 27. 
palliata, Say, 30. 
Sayii, Binn., 27. 
thyroides, Say, 28. 
MOLLUSCA, Ig. 
Mya complanatus, Solander, 86. 
margaritifera, Linn., 92. 
Mytilus fluvialis, Dillw., 93. 
OPERCULATA, 74. 
Pallifera, Morse, 20. 
dorsalis, Binn., 20. 
Paludina decisa, Say, 75. 
dissimilis, Say, 84. 
grana, Say, 80. 
limosa, Say, 79. 
lustrica, Say, 82. 
Nickliniana, Lea, 81. 
subcarinata, Say, 77- 
Patula, Hald., 45. 
striatella, Anth., 45. 
PECTINIBRANCHIATA, 74. 
PHILOMYCIDA, 18. 
Philomycus, 20. 
dorsalis, 20. 
Physa, Drap., 66. 
ancillaria, Say, 66. 
gyrina, Say, 67. 
heterostropha, Say, 67. 
hypnorum, Linn., 68. 
lata, Tryon, 68. 
Pisidium, Pfr., ror. 
abditum, Hald., 103. 
compressum, Prime, IOI. 
variabile, Prime, 102. 
virginicum, Gmel., 102. 
Planorbella, Hald., 69. 
campanulatus, Say, 69. 
10* 


INDEX. 113 
Planorbis, Miill., 69. 
albus, Miill., 72. 
armigerus, Say, 73. 
bicarinatus, Say, 70. 
campanulata, Say, 69. 
deflectus, Say, 71. 
dilatatus, Gould, 72. 
exacutus, Say, 71. 
parvus, Say, 72. 
trivolvis, Say, 70. 
var. fallax, Hald., 70. 
Planorbula, Hald., 72. 
armigera, Say, 73. 
Pomatiopsis, Tryon, 81. 
lapidaria, Say, 82. 
lustrica, Say, 82. 
Pseudo-hyalina, Morse, 43. 
minuscula, Binn., 43. 
PULMONIFERA, I8, 
Punctum, Morse, 48. 
minutissimum, Lea, 48. 
Pupa armifera, Say, 56. 
contracta, Say, 56. 
corticaria, Say, 57. 
decora, Gould, 58. 
exigua, Say, 60. 
fallax, Say, 56. 
Gouldiz, Binn., 59. 
milium, Gould, 59. 
PUPADA&, 51. 
Radix, Montf., 62. 
columella, Say, 63. 
macrostoma, 63. 
ROSTRIFERA, 74. 
Somatogyrus, 82. 
altilis, Lea, 83. 
Spheerium, Scop., 96. 
fabalis, Prime, 99. 
partumeium, Say, 100. 
rosaceum, Prime, 100. 
securis, Prime, IOI. 
simile, Say, 98. 
stamineum, Con., 99. 
striatinum, Lam., 98. 
transversum, Say, 97. 
