18 Remarks on Classifications of 



In this paper I propose to give particulars of, and observa- 

 tions especially upon the classifications* by II. & A. Adams? 

 (Genera of Recent Mollusca, II., London, 1855), and by Albers, 

 {Die Heliceen, Leipsic, 1860, 2d Ed., by Yon Martens), of the 

 species of Helix which inhabit North America, exclusive of the 

 Pacific Coast and Mexico. 



The following extracts from the lists of species given in the 

 former work will show the views of II. & A. Adams; the cor- 

 rections printed in Italic letters, are added by myself. 



Fam. HELICIDJ5. 



Subfam. HELICIN.E. 



Gen. Helix L. 



Subgen. Polymita Beck. 



varians Menke. V 



Gen. Ulacrocyclis Beck. 



Subgen. Vallonia Risso. 



annulata Case costata Miill. 



is exigua Stimp. pulcbella Miill. 



Gen. Anchistosiiaf Klein. 



Ariadnse Pfr. Dorfeuillianum Lea. 



auriculatum Say. Edgarianum Lea. 



avarum Say. fallax Say. 



cereolum Mublf. fraternum Say 



clausum Rat". is var. of monodon M. & R. 



is inflectiun Say, germanum Gould, 



convexum Raf. Hindsi Pfr. 



is monodon M. <£' M. bippocrepis Pfr. 



dentiferum Binn. hirsutum Say. 



* It is to be regretted that the first parts only of Gray's Catalogue of Fulino- 

 nata, London, 1855, and Guide to the Systematic Distribution of Mollusea, 

 London, 1857, issued from the British Museum, have at present been published. 



f " Shell orbiculately depressed, the umbilicus open or covered ; whorls 5-7, 

 the last dellexed at the aperture, often gibbous; aperture contracted, lunate, sub- 

 triangular ; peristome reflexed, usually dentate ; inner lip with a linguiform or 

 tooth-like callus, often uniting the margins." In the Synonymy of Anchistoma 

 H. & A. Adams have Stenotrema Raf., Ulostoma Alberts, Triodopsis Raf, Daeda- 

 locheila Beck, Isogonostoma Fitz., etc. Gen. of Recent Moll., II. 205. 



