15 



The word (Eu.) after the description of a species denotes 

 that the same is Hving also in Europe. One species, (H)- 

 alinia cellaria Mull.) is introduced from there, and possibly 

 one or two others may be found in Ohio (See Limax, note.) 



A few abbreviations could not well be avoided; they are: 



alt tor altitude. 



diam.. .for diameter. 



lam. . . . for lamella or lamellae. 



mill for millimeter or millimeters. 



sh for shell. 



sp for species. 



A-GENERA. 



1 Without an external sh. (slugs) . 2 



— with an external sh. 4 



2 mantle much shorter than the body, anterior; pulmo- 



nary opening near its right margin, behind the 

 middle; a rudimentary sh. plate under the mantle. 



1. Limax. 



— mantle nearly as long as the body; no sh. plate. 3 



3 70 to 100 mill, long; back with dark blotches and 



spots; jaw rather smooth with median part pro- 

 jecting. 12. Tebennophorus. 



— 18 mill, long; back rather uniformly ashy; jaw with 



strong ribs. 13. Pallifera. 



4 sh. too small to receive the soft parts, very thin, 



glassy, depressed, of 2 ^^ to 3 rapidly increasing 

 whorls, the last much the largest; diam. 6 mill. 



2. Vitrina. 



— sh. spacious enough for the soft parts to retreat. 5 



5 diam. of sh. surpassing the alt. 6 



— alt. surpassing the diam. 16 



6 peristome-margin straight and thin, or nearly so. 7 



— peristome-margin everted, with a distinct lip« 14 



