PLEUROCERA. 87 



broadly elliptical, or subrhombic ; within dirty- white or obscureh' 

 banded; columella deeply rounded, with a well marked sinus at base. 



Habitat. — Tennessee, near Athens. 



Observations. — Appears to be a very abundant and rather variable 

 species. Several hundred individuals have come under my notice. It 

 cannot well be confounded with any other species, though of a form 

 by no means uncommon! The sharp double carina} will at once gener- 

 ally determine it. Occurs abundantly near Athens, in small streams. 

 — Anthony. 



The figure illustrates one of Mr. Anthony's type specimens. 

 The following is the 3'oung of hicostatum. 



31. rigida. — Shell conic, elevate, carinate, rather thin; whorls 8-9, 

 carinate and banded ; sutures distinctly marked ; aperture small, ellip- 

 tical, whitish within; columella indented; sinus small -p- ,„, ,(,. 

 but very distinct. 



Habitat. — Tennessee. 



Observations. — This is one of those sharply keeled '^^^ 

 Melaniae of which M. bella, Conr., 31. carino-costata and ^H^"*^ 

 31. oblita, Lea, may be considered good examples. The 

 whorls of the spire have each two carina with generally a dark band 

 between them though this is sometimes wanting ; the body-whorl has 

 four or five of these carina} and generally two bands, one of which 

 revolves within the aperture. To the touch this species has a pecu- 

 liarly rough feel. — Anthony. 



Figure IGo is from Mr. Anthony's type. 



Fig. 166. J/, sugillata. — Shell acuminately turreted, livid gray, 



whorls ten to eleven, the first few encircled with 

 a very sharp keel, the rest smooth ; aperture rotun- 

 dately ovate, columella twisted, siuuately reflected at 

 the base. 

 Habitat. — Alabama. 



Observations. — Of a smooth, livid, bruised aspect, 

 encircled towards the apex with a particularly promi- 

 nent fine keel, which soon disappears. — Iteeve. 



The above figure is copied from Reeve. Gener- 

 alhj., but little dependence can ])e placed in the correctness of 

 the localities giveu for American species of JStrejio mat idee in 



