36 Cincinnati Society of Natural History. 



are to be left to stand on characters which seem to be far less well 

 defined. 



The hirsuta group is next in this regard, and when the varieties of 

 hirsuta and stenotrema, above mentioned, are taken into considera- 

 tion, the blending of the species into varietal forms is prett}' well 

 assured in one or two cases. It seems that the edvardsi group and 

 t\\Q spinosa group, of but two species each, though well enough char- 

 acterized to be distinguished as separate divisions of this genus, may 

 be united with 1\iq hirsuta group by several characters of greater or 

 less importance. It is not pretended that this grouping is of any 

 systemic value, whatever; but it will serve to call attention to the re- 

 lations whicli the species of this singular genus bear to each other, 

 and to their nearest allies in other genera, the genus gradually shad- 

 ing into Mesodon as represented by H. columbiana, Lea, through 

 If. germana, Gould. 



11. (Patula) cumberlan (liana., Lea. — I collected this beautiful spe- 

 cies durina: Au2:ust of 1878, in Franklin countv. Tenn. It inhabits 

 the lower slopes of the Sewanee Plateau, living in crevices of the sub- 

 carboniferous limestone. In places where the rocks have become sep. 

 arated, so that isolated masses lie on the mountain side, this curious 

 mollusk has taken up its abode between two la3'ers of the rock. It 

 often happened that the upper la3'er was thin, and the crevice thoroughly 

 dried out ; but in such apparently unsatisfactory places the shells 

 were found, the animal having closed the aperture with a transparent 

 but dense epiphragm. The locality is a small one, the whole area 

 within which it is possible to find the species being but a few hundred 

 square j-ards. As multitudes of the young shells are found dead, and 

 comparatively so few either of young or adult living, the fair inference 

 is that this rare species will at no distant day become extinct in this 

 place, A localit}^ of late years, unidentified, is Jasper, Tenn. I spent 

 some time in Jasper during August of 1878, but no sign of this shell 

 was discovered. In IMr. Binney's note under this species, in Terres- 

 t7nal llollusks, vol. v., he sa3's, " Helicina orbiculata, and a few 

 Y\h\iQ^^ alter nata found with them." The "variety" of H. alternata, 

 here mentioned, can not be the H. mordax, Shuttleworth, which does not 

 occur at this localit}-. I found the following species associated with 

 the cumberlandiana in the crevices ; H. spinosa, H. stenotrema, H. 

 hazardi, H. alternata; and numbers of the small southern scorpion, 

 Buthus carolinianus. Beauvois. The true H. mordax, of which I 

 have t3'pes kindl3' furnished me by Mr. Bland, is a very different shell 

 from the varieties between it and the t3^pical alternata.^ and is truly a 

 rare species. 



