eae. N Avail Us. 
VoL. XII. MARCH, 1899. Note 
CATALOGUE OF THE AMNICOLIDZ OF THE WESTERN UNITED STATES. 
BY HENRY A. PILSBRY. 
In the course of preliminary studies for a monograph of American 
species of this family, projected some years ago by Dr. C. E. Beecher 
and myself, I found that the Western species, or at least part of them, 
have been very imperfectly understood by most conchologists who have 
collected them. Thus, the name Bythinella or Pomatiopsis intermedia 
has been applied to several distinct species of middle California, a region 
where it does not occur. Bythinella binneyi and some Amnicolas have 
been equally misunderstood, and some of the Fluminicolas need revi- 
sion. I have, therefore, drawn up a list, with the localities of speci- 
mens in the collection of the Academy, and descriptions of some new 
species. 
With a view to extending our knowledge of the range of any of the 
species, I will willingly examine and identify specimens of the group 
for collectors desiring to have their shells compared with types or 
typical specimens of the several species. 
The types of Amnicola limosa, A.micrococcus, Paludestrina imitator, 
P. stearnsiana, P. hemphilli, Fluminicola columbiana, F. merriami, F. 
erythropoma, Pomatiopsis binneyi and P. californica, as well as of the 
synonyms Bythinella intermedia, Melania exigua and Amnicola turbini- 
formis, and author’s specimens or co-types of all of the other species ex- 
cept Fluminicola seminalis, are in the collection of the Academy of 
Natural Sciences. My opportunities for determining the status of the 
various species, and their synonymy, have therefore been favorable. 
Genus AMNIcOLA Gld. and Hald. 
A. micrococcus Pilsbry. Nevada: Small spring in Oasis Valley, 
Nye Co. (Merriam); Aurora, Esmeralda Co. (W. M. Gabb).  Cali- 
