302 



A MANUAL OF AMERICAN LAND SHELLS. 



Genitalia (/. c, Plate XIV, Fig. E). The genital bladder is large, 

 r>'- 322. oval, on a short, narrow duct ; the penis sac is 



long and stout, with a subcentral constriction; the 

 prostate gland is greatly developed. 



On Roan Mountain the shells are very thin. 

 A toothed variety is here ligured. The species 

 grows sometimes very niucli larger than the di- 

 M. Andretvsi, xai: meusious giveu above. Specimens received from 

 the mountains of North Carolina and Tennessee, collected by Mr. H. 

 Hemphill, show great variation from the shell originally described. 

 The extreme forms resemble the figure of M. major in Terr. Moll., 

 Ill, Plate I. I have examined over twenty specimens and find the 

 dentition resembling that of M. Andrewsi, and the genitalia also. The 

 penis sac is usually abruptly twisted at its center, which gives the con- 

 stricted appearance described by me. Mesodon major, found in com- 

 pany with M. Aw(7re?rs?', invariably has the lingual dentition and genitalia 

 described and figured by me in in Terr. Moll., V. I have figured here 

 two of this large form of M. Andreicfii : 



Fig. 322*. 



FUi. 323. 



M. Andrewsi, var. 



This is a noble species, which is justly dedicated to Mrs, G. Andrews, 

 of Knoxville, Tenn., to whom we are indebted for its discovery. 



Mesodon iiiiiltiliiicatus, Say. 



Shell imperforate, depressed-subglobose ; spire convex, rather thin; 

 epidermis yellowish-brown or russet-colpr, with nu- 

 merous reddish-brown, finely undulated, revolving 

 lines and bands; whorls between 5 and G, convex, 

 \ with delicate, parallel, oblique strite, the last ven- 

 tricose ; suture distinctly marked ; aperture lunate, 

 slightly contracted by the peristome; peristome white, 

 not much expanded, reflected, rather thin ; umbilical 

 region impressed. Greater diameter L'3, lesser 20"™; 

 height, 14'"'". 



M. multilmeaUis. 



i 



