212 Cincinnati Society of Natural History. 



more depressed, and much smoother, having a polished 

 appearance. There are also differences in the parts about the 

 aperture. Many years ago the now eminent explorer and 

 naturalist, Mr. Wm. Doherty, insisted upon having these dif- 

 ferences recognized by at least a varietal name. The same 

 treatment that has been accorded to many others of our land 

 shells would make a distinct species of this form, and lately 

 two or three of my correspondents have revived the sugges- 

 tion of varietal designation for it. I leave this with the book 

 makers. 



I will add, also, that I have taken, at Braden Mt., in Camp- 

 bell Co., Tenn., a still more aberrant variety. The shells are 

 very large, very much depressed, deeply sculptured, with the 

 denticles about the aperture little developed and remote. It 

 occurs in this locality with P. mordax Shutt., M. chilJunve^isis 

 Lewis, M. wetherbyi Bid. typus, a very small, deeply-sculp- 

 tured, and much-flattened variety of T. appressa, and fine 

 examples of very large specimens of Z. scjilpti/is Bid. The 

 variations in form, size, sculpture and coloring of this com- 

 mon species are, it seems to me, very suggestive. 



12. T. rugeli Shuttleworth. Two forms occur here. One 

 is found in the damper portions of the forest and is smaller 

 and less typically-developed about the aperture. The other, 

 found sparingly on the drier granite ridges, is two or more 

 times the cubic capacity of the first, and has the mouth parts 

 normal to the species as described. This variety is rare, and 

 the two grade into the following. 



13. T. iiiflecta Say. This species is abundant here with no 

 special variation from the type. In size it agrees with the 

 smaller variety of the preceding. 



The above four species are all that we have yet found here 

 belonging to Triodopsis. 



T. introfcrcns Bid. has been found in neighboring coun- 

 ties South of us, and may yet turn up here. 



Stenotr1':ma (Rafincsque, i8ig). 



14. ^. hirsutnm Say. This shell occurs here somewhat 

 abundantly, in two forms; one is typical, much like the speci- 

 mens found about Cincinnati. The other variety {aitispira 



