of North American Helicidce. 109 



II. monodon Rack., umbilicus open. 



Diam. maj. 11, min. 10, Alt. h\ mill (6.j whorls), Texas. 

 " " 7 " 6 " 4 " (5i " ), N. Car. 

 II. fraieima Say, umbilicus entirely closed. 



Diam. maj. 10, rain. 9, Alt. 5 mill (of whorls), Goat Isl.,N.Y. 

 " " 1\ " U " 4 '• (5i " ), Alabama. 



I have three specimens of II. monodon^ sent to me by Mr. 

 Sloate, formerly of San Francisco, who assured me, on the 

 authority, however, of another person, that they were found 

 near the mouth of the Columbia River, Oregon. I confess that 

 I do not feel satisfied of the correctness of the statement. 



H. Leaii "Ward is the most striking variety, if not indeed 

 entitled to specific rank ; it inhabits by no means so wide an 

 area as II. monodon or the var. H.fraterna., being found only, 

 I believe, in Michigan, Iowa, Indiana, and Ohio. Mr. Frank 

 Higgins, in his Catalogue of the Mollusca of Columbus, Ohio, 

 insists on its being distinct. He says that it is found in the 

 swamp prairies only, its station being very dififerent to that of 

 H. monodon^ and that it never appears to extend its range, and 

 does not vary in color of shell or animal. 



Mr. A. O. Currier, of Grand Eapids, Michigan, in a late 

 letter remarks, " H. monodon and II. Leaii have entirely dif- 

 ferent habits, the former is abundant in dry, the latter rare in 

 moist situations and swamps associated with Aimnicola lapi- 

 daria Say, and other semi-aquatic species. II. Leaii lives during 

 half the year under water and ice, while E. monodon is found 

 under the bark of trees and rotten stumps. If their stations 

 were changed both would become extinct." 



The measurements of my largest and smallest specimens are, 



Diam. maj. 8, min. 7, Alt. 4 mill. (5i whorls), Ohio. 

 « '' 7 " 6 " 3i " (5 " ), " 



Helix appressa iSay. 



This species is variable in several characters. In Georgia it 

 attains its greatest size ; from that State I have examples with 



2 



