108 Mr. Barnes on the Genera Unio and Alasmodonta. 
liberality of Mr. H. R. Schoolcraft, Mineralogist to the ex- 
pedition, who collected them at the expense of much volun- 
tary fatigue, transported them a thousand miles, and gene- 
rously distributed them among the lovers of Natural Science, 
in New-York and Philadelphia. : 
A second parcel was soon after received from Capt. D. 
B. Douglass, Professor in the Military Academy at West- 
Point, and topographical oe to the expedition, whose 
avowed object, in sending his collection, was that it might 
be arranged and described for the American Journal of 
Science and Arts. To this gentleman we feel ourselves 
much indebted, for his valuable and detailed account of the 
localities of his specimens. What adds to the value of these 
collections, is, that independent of the numerous species 
and varieties before unknown, the specimens of the previous- 
ly ascertained species are in many instances, remarkably 
a and beautiful. 
1. Lamarck, in the sixth Volume of his “.2nimaux sans 
Vertebres,” bas described twenty-sic* species of North 
American Uniones. He was moreover in doubt of the lo- 
calities of several others, which will probably be found to be 
American. Whether he has, as we strongly suspect, deseri- 
bed some of our species under four or five different names, 
cannot be certainly determined, as his book contains no fig- 
ures, and the descriptions are short and equivocal. The Unto 
purpureus of Mr. Say, purpurascens of M. Lamarck, is 
common in all our eastern waters, and has a different ap- 
pearance from every locality. In the Hudson it is small 
and short; in the Housatonick, long and slender; in the 
Saratoga Lake, of middling size; in the Kayaderosseras, 
thick and heavy ; in the Lakes of New-Jersey, large and 
ponderous. If these are to be made different species, we may 
as well make four or five different species of the common 
clam, Venus mercenaria, Linn. from as many different local- 
ties around New-York. They are really unlike. Not on- 
ly is the appearance of the shells different to the eye of the 
naturalist, but also the taste of the included animals, to the 
palate of the epicure. Who does not know that the Indian 
corn, Gea Jays, assumes a different appearance in every 
latitude from Quebec to Florida? Yet whoever thought of 
* For eight of these, he quotes Mr. Say’s book, which contains nine. 
