26 



This is a short, wide species, sufficiently distinct from others, 

 and readily distinguished by the lamina of the labrum being much 

 elevated, and by the magnitude of the tooth of the labium. I 

 obtained two specimens at Occoquan, under a pile of bricks and 

 rubbish. This species probably belongs to the genus Carychium. 



P. EXIGUA. — Shell dextral, tapering, oblong, with minute 

 grooved lines ; apex obtuse ; whorls five ; suture deeply impressed ; 

 labium bidentate, superior tooth situate rather beneath the middle 

 of the lip, inferior tooth small, placed on the columella ; labrum 

 mutic, reflected, but not flattened ; umbilicus distinct. 



Length more than one-twentieth of an inch. 



This is the smallest species that I have seen. Numerous speci- 

 mens of it were found near this city by Mr. William Hyde, and I 

 have obtained many at Harrigate. Its aperture resembles that of 

 Pupa (Carychium) corticaria, but the superior tooth of the labium 

 of that shell is situate much nearer to the superior termination of 

 the labrum than the corresponding tooth of this diminutive species. 

 It is probably a Carychium. 



Genus Vertigo — Muller and Ferussac. 



P. (vertigo) ovata. — Shell dextral, subovate, brown ; apex 

 obtuse ; whorls five, glabrous ; suture not very deeply impressed ; 

 body whorl indented near and upon the labrum ; aperture semi- 

 oval ; labium five-toothed, of which three are situate on the trans- 

 verse portion of the lip, parallel to each other, equidistant, the 

 superior and inferior ones being small, the latter sometimes 

 obsolete, the intermediate one lamelliform, prominent, and the two 

 others situate on the columella, approximate, extending at right 

 angles to the three preceding ones, the superior one oblique and 

 smaller ; labrum reflected, but not flattened, bidentate, teeth 

 lamelliform, prominent ; umbilicus distinct. 



Length less than one-tenth of an inch. Breadth nearly one- 

 twentieth of an inch. 



Animal — tentacula 4,wo, rather long and thick, cylindrical- 

 obconic, retractile, with a rounded oculiferous extremity ; foot 

 white; head and neck, as far as the mantle, black. 



Inhabits Pennsylvania Numerous specimens were discovered 

 by Mr. William Hyde in the vicinity of this city, and I obtained 



