iOd Mr, Barnes on the Genera Unio and Alasmodonia, 



liberality oi 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 Nf w-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 engineer 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 

 large and beautiful. 



M. Lamarck, in the sixth Volume of his ^^Animaux sa7is 

 Vertehres,''^ has described twenty-six* 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, descri- 

 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 Unio 

 purpureus of Mr. Say, purpurascens of M. [jomarck, 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, Zea Mays, assumes a different appearance in every 

 latitude from Quebec to Florida? Yet whoever thought of 



* Foir eight o{ these, he quotes Mr. Say's book, which coataitis jiine. 



