SYSTExMATIC INDEX. 



IX 



85. 



86. 



87. 

 88. 

 89. 



90. 

 91. 



92. 

 93. 

 94. 



95. 



96. 

 97. 



99. 

 100. 

 101. 

 102. 

 103. 



104. 

 105. 



106. 



Page 



Piano rbis haldemani, Dkr. 

 110 



Adula, H. Adams. Ill 



Planorbis multivolvis, Case. 

 Ill 



Ilelisoma, Swains. 112 



Planorbis ammon, GId. 112 

 Planorbis tenuis, FhiL 113 

 Planorbis corpulentus, -Sf/j/. 



114 

 Planorbis trivolvis, Say. 115 

 Planorbis truncatus, Miles. 



121 

 Planorbis fragilis, De K. 122 

 Planorbis lautus, //. Ad. 123 

 Planorbis bicarinatus, Say. 



123 

 Planorbis antrosus, Con. 125 



Menetus, H. & A. Ad. 125 



Planorbis operoularis, Gld. 



125 

 Planorbis ezacutus, Say. 



126 



Gyraulus, Ag. 128 



Planorbis vermicularis, Gld 

 128 

 Planorbis deflectus, Say.l2d 

 Planorbis dilatatus, Gld. 131 

 Planorbis albus, Mull. 132 

 Planorbis parvus, Say. 133 

 Planorbis arcticus, Beck. 135 



Segnieiitiiia, Flem. 136 



Planorhida, Hald. 136 



Segmentina "wheatleyi.Z^ea. 



136 

 Segmentina armigera, Say. 



137 



ANCYLIN-S3. 



138 



Ancyliis, Geof. 138 



Ancylus obscurus,//aW. 139 



Page 

 107. Ancylus fuscus, Ad. 140 

 1U8. Ancylus elatior, Anth, 140 



109. Ancylus diaphanus, Hald. 



141 



110. Ancylus haldemani, Boury. 



141 



111. Ancylus sallei, Boury. 142 



112. Ancylus parallelus, Hald. 



142 



113. Ancylus rivularis, Say. 142 



114. Ancylus tardus, Say. 143 



115. Ancylus calcarius, De K. 143 



116. Ancylus patelloides, -tea. 



144 



117. Ancylus kootaniensis, 



Baird. 144 



118. Ancylus caurinus. Coop. 144 



119. Ancylus newberryi,Z,ea.l45 



120. Ancylus crassus, Hald. 145 



121. Ancylus fragilis, Tryon. 146 



122. Ancylus ? filosus, Con. 147 



123. Ancylus borealis, Morse. 156 



Acroloxus, Beck. 147 



124. Acroloxus nuttallii,iea. 147 



125. Acroloxus ovalis, Morse. 156 



Oundlachia, Pfb. 148 



126. Gundlachiacalifornica.iiit;^. 



149 



127. Gundlachia meekiana, 



Stimp. 150 



SuBORD. THALASSOPHILA. 152 

 SIPHOXARIID^. 152 



Siphonaria, Blainv. 152 



128. Siphonaria alternata, Say. 



153 



129. Siphonaria aequilirata, Cjor. 



153 



130. Siphonaria amara, Rve. 154 



131. Siphonaria lecanium, Phil. 



154 



