440 PROCEEDINGS OF THE ACADEMY OF [^^^Y, 



Avell developed, tliougli rather more roimdcd tlian in var. carinata 

 Pils., but the under side just below the carina is distinctly concave, 

 as in Pyramidula hryanti. This disappears somewhat in full-grown 

 specimens toward the aperture, but is always evident on the first 

 Iwo-lhirds of the last whorl, and is particularly marked in the 

 young shells. The micro-sculpture is well developed, consisting of 

 very fine irregular lines of growth between Ihe ribs, which are cut 

 transversely by numerous fine revolving lines. The only difference 

 observable in these shells is that of size. Of our sj)ecimens 

 none equals the dimensions given by Shuttleworlh. Our largest 

 example has a greater diameter of 17^, lesser 15, with an altitude 

 from the base of 6| mm. If Shuttle worth's types measured only 

 6 mm. from the basal lip, they are more lenticular than any form 

 of alternata yet known, and the true morclax yet remains to be dis- 

 covered. It is probable, however, that Shuttle worth followed Pfeiffer 

 in measuring the height from the base of the axis. 



The form here figured as P. a. mordax seems to be confined to a 

 particular zone on the mountainside, and does not appear to mix with 

 the smooth form of alternata. " It has the same habits as the com- 

 mon form, around old basswood and tulip tree logs, but the two 

 were never together Mordax dwelt in the tulip tree belt, and 

 the common form was both above and below, but never in . that 

 belt" (J. H. F.). 

 Pyramidula perspectiva (Say). 



Paint Rock, on both sides of the river, fairly abundant; scarce 

 in Wilson's Cove, and a single specimen only from Cat-tail. 

 Pyramidula bryanti (Harper). 



The original description of Harper'" is not as full in detail as 

 could be desired. Wether by 's observations^** are far more exact 

 and give a better idea of the specific characters. As he states, 

 " the whorls are heavily ribbed above and below, the rib termi- 

 nating at a sharp angle on the upper and uiider outer edges of the 

 body whorl, leaving a concave space between, which is compara- 

 tively smooth." In occasional specimens, however, toward the 

 aperture the ribs, in a less developed form, are carried across from 

 one carina to the other. The types came from Mitchell county, 

 N. C, and probahly from Roan mountain. At any rate. Roan 

 mountain .specimens are quite typical in every respect. Typical 



^''Jour. Cincinnnti Soc. lif. H., 1881, p. 258. 



■'"Jour. Cincinnati Soc. N. H., 1881, p. 338. Reprint, p. 7. 



