195 



[On page 4 of cover of Am. Con. p. iv.] 



Notice. — In the last No. I remarked that the Alasmodonta confragosa, 

 nob., was found by Mr. Barabino near the city of New Orleans ; this is 

 an error altogether my own, and which I thunk that gentleman for ena- 

 bling me to correct. He obtained his specimens from Bayou Teche in 

 the Parish of St. Mary, Louisiana, about two hundred miles N. N. W. 

 from New Orleans. I did not suppose they were found in the Mississip- 

 pi, and my interesting correspondent says, ' ' I have not yet discovered 

 any bivalves in the Mississippi, (near New Orleans), although I have 

 tried two summers successively, with an instrument made for that pur- 

 pose." 



The Ampularia urceus, L. {rugosa, Lam.) is stated in the books to in- 

 habit the Mississippi river ; but I have never been so fortunate as to find 

 it, or to gain any information relative to it there. Mr. 0. Evans did me 

 the favor to make enquiry at various places on that river, and to exhibit, 

 as somewhat similar, a colored plate of the A. globosa, Swains., to per- 

 sons from whom information might be expected, and amongst others to 

 some Indians, who in general are known to be accurate observers ; but 

 no one has seen any similar shell in the waters of the Mississippi. I am 

 therefore much inclined to believe that the species is a native of some 

 of the more southern rivers, probably those of Texas. Any informa- 

 tion in relation to it, or specimens of the shell, will be very acceptable. 



[Am. Con., p. v. Aug. 1832.] 



Unio lapillus. — Specific character. Very small, thick, radi- 

 ated ; teetli very thick. 



U. lapillus, nob. Transylvania Journal of Medicine. Vol. 4, 

 p. 528. . 



Desc. Shell transversely suboval, thick, obscure yellowish, with 

 very numerous dark green radiating lines : posterior margin not 

 very short, rounded : beaks but little elevated, simple : lunule 

 fusiform, very obvious : hinge margin and anterior margin a little 

 depressed, declining gradually in an arquated line : anterior basal 

 margin rounded : basal margin nearly rectilinear in the middle : 

 within pearly white ; cardinal teeth direct, thick ; lateral teeth 

 thick, oblique with respect to the base : cicatrices very deep and 

 rounded : cavity of the beaks almost obliterated, with a series of 

 small cicatrices, extending downwards and backwards. 



Ohs. The robust teeth and the thickness of the whole shell. 



