er | EE = EP 
NOTES ON THE UNIONIDA OF FLORIDA AND THE SOUTHEAST- 
ERN STATES. 
By Cuartes T, Simpson, 
Aid in the Department of Mollusks, U. S. National Museum. 
(With Plates XLIX-LXXIV. ) 
INTRODUCTION. 
For some years past [ have made a special study of the Unionide of 
Florida and the southeastern States, their variation and distribution, 
and I have been led to prepare the following catalogue and notes prin- 
cipally for two reasons: 
First. There are undoubtedly very many so-called species of unios 
from this region that are merely trifling variations of valid forms or 
actual synonyms, and which only serve to cumber our literature and 
embarass the student. Dr. Lea, our great authority, seemed in many 
instances to fully understand this wide variation, and he has often 
grouped together under a single name shells which at first sight seem 
to be distinet, but which, when carefully studied with other material, 
are seen to be but varieties of one thing. But in other cases he has 
founded species on trifling «and inconstant characters, and has repeat- 
edly given different names to what are evidently identical forms. 
More recently the Wrights (Messrs. 8. H. and B. H.) have collected 
in the lake region of Florida, they have made a study of the Unionide 
of the State, and have published quite a number of new species; but 
they do not appear to have worked up their material with sufficient 
thoroughness, as a number of their new wnios are certainly varieties of 
well-known forms or actual synonyms of hitherto named species from 
Georgia, Florida, and the Carolinas. 
Secondly. Much confusion exists among collectors and students re- 
garding the material in their collections, a considerable proportion of 
the shells from this region having been sent out under wrong names. 
Fully one-half these species are not understood, and the cabinets of 
conchologists in general exhibit the most deplorable confusion in this 
matter. 
It is my desire in this list to considerably reduce the number of so- 
called species by showing that they vary into each other, or that many 
of them have without proper study simply been assumed to be new and 
renamed, and to give such descriptions and notes as will materially 
assist in properly determining material. 
Proceedings National Museum, Vol. XV, No 911. 
405 
