— 
Notes on American Land Shells. 325 
found at elevations varying from 3,000 to 3,500 feet, in the leaves about 
the loose rocks of tali, under cliffs, and occasionally under logs. The 
station of the large varieties mentioned above, is always near or at the 
base of limestone cliffs. I. chilhoweensis inhabits the open forest. 
6. Mesodon andrewsi, W. G. Binney.—Besides the typical form of 
this shell, recently described by Mr. Binney, there occurs on the south- 
east slope of Roan, a large variety, having nearly twice the cubic capacity 
of Mr. Binney’s type. The shell agrees well with his description of 
M andrewsi in nearly every other particular. The type of I, andrewst 
was a thin shell, while these are quite solid in texture, of lighter color, 
and of more ponderous make up generally. But one animal was 
secured. This much resembled that of H. thyroides, except that the 
oculiferous tentacles were much shorter and stouter. The animal is 
very timid and sluggish. The species is comparatively rare, though a 
fair number of specimens. was found. It is evidently a distinct, and 
well marked form. 
7. Mesodon wetherbyi, Bland.—Shells which have been referred to 
this species oceur somewhat sparingly at this locality. Like the speci- 
mens from the original station, the shells are covered with a thick 
coating of dirt, imbedded in the hirsute covering of the epidermis, 
which being carefully washed away leaves the shell of a pale greenish 
white color. These shells have a lamellar projection on the inferior 
surface of the peristome much like that of some varieties of 7. appressa, 
and which is a character very distinct from that of the same region in 
‘the type. A very careful examination of the genitalia shows them to 
be much more like those of Zriodopsis. Indeed, looking over the 
whole field, it seems not improbable that here we have another case of : 
the union of characters of Mesodon with other groups, like that of 
Stenotrema, mentioned in my notes, No. 1. Mr. Binney says, Terr. 
Moill., vol. v., p. 301, “ Lriodopsis does not differ from Mesodon or 
Polygyra in the character of its jaws.” Again, p. 306, ke says that 
the genitalia of 7. appressa, resemble, in certain features, those of 
Mesodon sayii=M. diodonta. ‘This shell certainly presents as many 
features that would ally it to Zriodopsis through appressa, as to 
Mesodon through dentifera. In fact, | am inclined to the belief that 
the shell is not Mesodon wetherbyi at ail. but a distinct species, proba- 
bly a Zriodopsis, and having the closest anology to MM. dentifera, 
Binney, which certainly has some very strong claims to relationship 
to Triodopsis through J. appressa. The station of this species is 
always in the dirt under and beside rotting logs. It is very sluggish 
and timid, and very rare. 
