516 APPENDIX. ' 



species were also observed by Mr. Say, as far east as the Falls of 

 Niagara. 



LYMNEUS. 



5. Lymneus umbrosus, Saj/, Am. Con. iv. pi. xxxi. Fig. 1. 

 Lake Winnipec, Upper Mississippi, and Eainy Lake. 



6. Lymneus reflexus. Say, 1. c. pi. xxxi. Fig. 2. Eainy Lake, 

 Seine River, and Lake Winnipec. 



7. Lymneus stagnalis. Lake a la Crosse, Upper Mississippi. 



PALUDINA. 



8. Paludina ponderosa, Say. Wisconsin River. 



9. Paludina vivipara. Say, Am. Con. i. pi. x. The American 

 specimens of this shell are more depressed than the European, 

 but appear to be identical in species. 



MELANIA. 



10. Melania virginica. Say. Lake Michigan. 



ANODONTA. 



11. Anodonta cataracta. Say. Chicago, Lake Michigan. 

 • This species, Mr. Lea remarks, has a great geographical extension. 



12. Anodonta corpulenta. Nobis. Shell thin and fragile, 

 though less so than others of the genus ; much inflated at the 

 umbones, margins somewhat compressed; valves connate over 

 the hinge in perfect specimens ; surface dark brown, in old shells ; 

 in younger, of a pale dingy green, and without rays, in all I 

 have examined ; beaks slightly undulated at the tip. The color 

 within is generally of a livid coppery hue, but sometimes, also, 

 pure white. 



Length of a middling sized specimen, four and a half inches, 

 breadth, six and a quarter. It is often eighteen inches in circum- 

 ference round the border of the valves, with a diameter through 

 the umbones of three inches. Inhabits the Upper Mississippi, 

 from Prairie du Chien to Lake Pepin. 



This fine shell, much the largest I have seen of the genus, was 

 first sent by Mr. Schoolcraft, to the Lyceum, several years ago. 

 So far as I am able to discover, it is undescribed, and a distinct 

 and remarkable species. It may be known by its length being 



