QUATERNARY AGE. 287 



MOLLUSKS IN THE LoESS DEPOSITS. 



The following list of land and fresh-water shells comprises all 

 that I have thus far identified, in whole or in part, from the Loess 

 deposits. Nearly all are extremely fragile. The Hyalinas, Pupas, 

 and some of the Helices long eluded my efforts at identifying them. 

 I finally marked the localities where found, until the ground was 

 frozen, when they were cut out with a knife. They were then 

 identified bv making thin sections with a sharp knife. Many of 

 these mollusks, after being placed for a while in my cabinet, fell to 

 pieces. For this reason I have no specimens to show of many 

 species here given, and, therefore, only present this as a provisional 

 list. Some well-preserved specimens appear to me to be new to 

 science, but as I have not access to the descriptions of the new 

 species discovered by Harden, a bare list of which is given in Bin- 

 ney's and Bland's Land. and Fresh Water Shells, I will not ven- 

 ture to describe them, as that has probably already been done. The 

 counties are indicated where the specimens were obtained, or where 

 thev were the most abundant. 



In addition to my own list of species, which were first published 

 in the Hayden Reports for 1S74, Prof. J. E. Todd has given 

 eighteen from the Loess of Iowa. Prof. Swallow also reports fifty 

 species from the Loess of Missouri, twenty of which are fresh- 

 water shells: 



Vitrina limpida, Gould, Lancaster and Dixon Counties. 



Hvalina nitida? Mueller, Dixon Countv. 



Hvalina arborea, Say, Douglas and Dakota Counties. 



Hvalina viridula, Monke, all Eastern Nebraska. 



Hvalina indentata, Say, Otoe and Douglas Counties 



Hvalina limatula, Ward, Douglas County. 



Hvalina minuscula, Binney, all Eastern Nebraska. 



Hvalina binneyana? Morse, Dixon and Cedar Counties. 



Hvalina ferrear Morse, Dixon County. 



Hyalina exigua, Stimpson, Dixon and Cedar Counties. 



Hvalina intertexta? Binney, Douglas Countv. 



Hvalina ligera, Say, Otoe and Nemaha Countie-. 



Hvalina demissa? Binney, Nemaha and Richardson Counties. 



Hyalina fulva, Dreparnaud, Dixon and Cedar Counties. 



Hyalina lasmodon, Phillips, Nemaha and Otoe Counties. 



Hyalina interna, Sav, Nemaha and Otoe Counties 



