CONCHOLOGY. 



7. ff. minuta. Shell rather thick ; spire 

 convex, little elevated, with three volu- 

 tions ; suture well defined, impressed ; 

 whorls obtusely wrinkled across ; aper- 

 ture nearly orbicular ; lip much thicken- 

 ed, reflected, white, distant from the um- 

 bilicus ; umbilicus large, exhibiting the 

 volutions. 



Breadth less than one-tenth of an inch. 



Jour. Acad. JVat. Sciences, vol. i. p. 124. 



Found under the bark of a decaying 

 oak ; is readily distinguishable from other 

 species by its small size and conspicuous 

 lip. It is a true Helix. 



8. H. labyrinthica. Shell conic, dark red- 

 dish brown, body lighter ; whorls five or 

 six, with conspicuous, elevated, equidis- 

 tant, obtuse lines across, forming grooves 

 between them ; apex obtuse ; lip reflect- 

 ed, rounded ; pillar lip with a large, la- 

 melliform, elongated tooth, which ap- 

 pears to revolve within the shell parallel 

 to the suture, a smaller raised line re- 

 volves nearer ,to the base within the 

 shell, but becomes obsolete before it ar- 

 rives at the pillar lip ; umbilicus rather 

 large. 



Breadth one tenth of an inch. 



Jour. Acad. JVat. Sciences, vol. i. p. 124. 



Found on fungus in decaying wood : 

 this shell is remarkable for the two much 

 elevated lines, which revolve within the 

 shell upon the penultimate whorl, the up- 

 per one larger, and terminating at the 

 aperture very conspicuously, and resem- 

 bling a tooth. 



9. H. ffirsuta. Shell subglobose, brown- 

 ish, iinperforated, covered with short, nu- 

 merous, rigid hairs ; whorls five, but little 

 rounded ; suture distinct ; aperture very 

 narrow, almost closed by an elongated, 

 lamelliform tooth, situated on the pillar- 

 lip, and circularly joined to the outer-lip 

 at the base. Outer-lip reflected back up- 

 on the whorl, and incorporated with it 

 near the base, with a deep sinus in the 

 middle. Breadth one-fourth of an inch. 



Lister, tab. 93. f. 94? 



Inhabits moist places. Common. 



This species appears to be somewhat 

 allied to the H. hispida, but is sufficiently 

 distinct. Found by Mr. Lardner Vanux- 

 em. It approaches the genus Caprinus 

 Montf. but differs in having the lips disu- 

 nited above. 



10. H.perspectiva. Shell very much de- 

 pressed, with about six whorls ; whorls 

 striated across, with raised, parallel, acute 

 lines, forming strongly impressed sulcae 

 between them. Umbilicus very large, 



resembling an inverted spire, in diameter 

 at least equal to the breadth of the body 

 whorl, and exhibiting distinctly all the vo- 

 lutions. Diameter three-tenths of an inch. 



Journal Acad. JVat. Sciences, vol. i. p. 18. 



Found by Mr. Le Sueur, near Lake 

 Erie. It is referable to the genus Zoni- 

 tis, Montf. 



11. ff. Lineata. Shell very much depress- 

 ed, somewhat discoidal. Whorls about 

 four, each longer than broad, with nume- 

 rous, raised, parallel, equidistant, regular, 

 revolving lines. Suture impressed. Um- 

 bilicus very large, diameter at least equal 

 to the body whorl, and exhibiting all the 

 volutions distinctly. Aperture longer 

 than wide, lunate. Diameter three-twen- 

 tieths of an inch, nearly. 



Jour. Jlcad.Nat. Sciences, vol. i. p. 18. 



Found by Mr. Robert E. Griffith, near 

 Philadelphia. Somewhat resembles the 

 last, but is more depressed, and the striae 

 are transverse, not longitudinal as in that 

 shell; the cavity beneath also, though of 

 equal proportional diameter, is not pro- 

 portionally deep. Belongs to the genus 

 Zonitis, Monf. 



GENUS POLTGTRA. 



Shell discoidal, more or or less carinat- 

 ed on the upper edge of the whorls, um- 

 bilicated; aperture longer than broad; 

 lips thickened, toothed, or folded and 

 continued, folds concave beneath ; pillar- 

 lip raised above the preceding whorl, and 

 concave beneath. 



Animal granulated; tentacula four; 

 eyes at tip of the superior tentacula and 

 retractile ; operculum none. 



1. P. Jluriculata. Shell beneath convex ; 

 whorls five, a little rounded, crossed by 

 numerous raised equidistant lines, form- 

 ing grooves between them ; spire very 

 little raised ; lateral line (extending from 

 the outer whorl to the apex) not convex, 

 but somewhat concave ; mouth very une- 

 qual; lips prominent above, and pressed to 

 the preceding whorl beneath ; pillar-lip 

 suddenly reflected, and pressed into the 

 mouth at an acute angle, beneath very 

 acutely concave ; outer-lip a little more 

 prominent in the middle, and within the 

 edge protruded into the mouth ; throat 

 extremely narrow ; suture near the mouth 

 suddenly reflected from the preceding 

 whorl, and carinate ; umbilicus dilated, 

 very small within, and exhibiting 1 a groove 



