324 Cincinnati Society of Natural History. 
tended higher than the margin of the bald, and none of the larger 
species, of the genus Mesodon, were found by me at an elevation of 
more than 4,500 feet. 
I can not say what has been the experience of others in this regard. 
1. Mesodon major, Binney.—This shell, which has always been held 
by Mr. Bland to be a variety of MZ. albolabris, Say, is undoubtedly 
distinct. I obtained quite a large number of individuals, many of 
which were much larger than Mr. Binney’s type, from an old windfall, 
where they were found crawling over the rotting logs very early in 
the morning and late in the afternoon, in wet weather. The animal is 
quite distinct from the albolabris, and the shells decidedly so. Among 
the shells were several albinos, and a variety of forms resulting from 
the comparatively greater or less elevation of the spire. The remarks 
of Mr. Binney on the shells and animal of this species, Terrestrial 
Mollusks, vol. v., pp. 316, 317, are verified by my observations. Found 
with these shells, and in precisely the same station, was a dentate 
variety of MW. albolabris, Say. I régurd this fact of the association of 
two distinct, but closely allied forms, in the same habitat and station, 
as a very suggestive one, which probably points either to peers dif. 
ferences or to the theory of geological remnants. 
2. Mesodon albolabris, Say.—This species was found with the last, 
and was in every way, except in the presence of the parietal tooth, the 
normal type of the species. The shells are not as large as the ordinary 
form, and the lip is a trifle more widely reflected. The animal is 
much more active, and far less timid than that of M. major, as I had 
every opportunity to observe. I think that any collector who has the 
Opportunity to observe these two shells in their native haunts, will not 
hesitate to regard them as being decidedly distinct, differing so widely 
as they do in size, coloration (of animal), habits, ete. 
3. Mesodon exoleta, Binney.—This shell was found, somewhat 
sparingly, exhibiting no peculiar features. 
4, Mesodon thyroides, Say. Very rare in this locality. A few dead 
shells only found. ) | 
5. Mesodon diodonta, Say.—This shell was found in considerable 
numbers, represented by a small, pale, thin variety, resembling speci- 
mens which I have had from Vermont, Maine and New York. It was 
in striking contrast with the large, heavy variety, found in Kentucky 
and Tennessee, and still more with the M. chilhoweensis, Lewis, found 
in the mountains of the western part of the metamorphic belt, and 
which has been called a variety of If. diodonta, Say. This species was 
