NATURAL SCIENCES OF PHILADELPHIA. IS 
s 
Mr. Lea remarked, that he had received from Dr. Hayden, so well known for 
his interesting discoveries of the fossil Fauna, of Nebraska Territory, &c., all 
the fresh water molluscs which he had procured during his journey into those 
distant and little known Indian countries. Mr. R. Kennicott, a young and ardent 
student of Natural History, whose letter Mr. Lea read, had also submitted to him a 
collection of molluscs made by him for the Northwestern University of Evanston, 
Illinois, from a part of North America rarely visited by the investigator of Nat- 
ural History, the Red River of the North, which having its source near the head 
waters of the Mississippi, runs due north into Lake Winnepeg, which Lake dis- 
charges its waters through Nelson's River into Hudson's Bay. 
It is not to be understood that either of these collections, made under many 
adverse circumstances, and at times, of great personal danger, should be full 
representations of this branch of the Fauna of these countries. But they are 
sufficient to prove that zoological life, so far as represented by IIoUuscs, is nearly, 
if not quite the same, as that of the Ohio River Basin, as well as that of the 
Missouri River, and a part of that of the Lower Mississippi and Red River of the 
South. The knowledge of a part of the species from these remote districts, 
proves to us the wide-spread distribution of the same species, as we find evenr 
one of them in the Ohio River at Cincinnati, Marietta and Pittsburg, and this is 
the more remarkable, as the waters of the Red River of the North are embraced 
in a different system of drainage, flowing as they do into Hudson's Bay at about 
52° North lat. Thus is seen an immense area of country producing in its waters 
nearly the same life, as regards the Molluscs ; a fact highly interesting to the 
Zoologist. 
The following species were brought by Dr. Hayden from the mouths of the 
Rivers Big Sioux and James' River, 43° north, and 9*7° west, 
Unio asperrimus, Lea. U. elegans. Lea. U. alatus. Say. U. lacrimosus. Lea. 
U. laevissimus. Lea. U. luteolus. Lam. U. rectus. Lam. U. anodoiitoides, Lea. 
Margaritana complanata. Lea. 
And from the Upper Missouri at Fort Clark, Unio luteolus, Lam., and Margari- 
tana complanata. Lea. 
From the Red River of the North, 50° north, Mr. Kennicott procured the fol- 
lowing : 
Unio asperrimus. Lea. U. alatus, Say. U. luteolus, Lam. U. rectus, Lam, 
U. rubiginosus. Lea. U. occidens. Lea. U. undulatus, Bar. Anodonta Ferus- 
saciana, Lea. A. decora, Lea. 
Every species from these two habitats is found in the vicinity of Cincinnati, 
and several of them, viz : Unio asperrimus, anodoiitoides, rubiginosus, and Ano- 
donta Ferussaciana are found in the waters of Louisiana. Even in Georgia there 
are two of them, viz : Unio anodontoides and Unio alatus. 
Mr. Lea did not wish to be understood that he believed all the species of the 
Unionidce, which were common in one part of this great area, were the same which 
inhabited the waters of other parts. On the contrary, they differed much in the 
lower Mississippi, but still there are some species which are common in the 
Ohio, as high up as Pittsburg, which are found in Moose River, of Hudson's Bay, 
52° North, in Red River of the north, 50° North, in Upper Missouri, 4Y° North, 
and in the Big Sioux, 43° North. There are also some others which are com- 
mon at Pittsburg, which are found as far south as Louisiana, 30° North, and in 
Georgia, 34° North. 
These facts Mr. Lea believed to be important in regard to the geographical 
distribution of the species, some of which are found to bo so extensively dis- 
tributed, while it is well known that some few are restricted, so far as our present 
knowledge extends, to points embraced within very short distances in a single 
river. As an illustration of this, the Unio spinosus, Unio Shepardianusy Margari- 
tana arculn, &c., may be cited. 
1858.] 
