126 LAND AND FRESH-WATER SHELLS OF N. A. [PART L 



— Var. a, b, DeKat, N. Y. Moll. 33, pi. ii, f. 16 (1843).— Var. 



BiNNEY, Terr. Moll. II, 137, pi. xv. 

 Helix appressa, var., Deshayes in Fer. (in plate, not in text). 

 Helicodonta denotata, var., Fekussac, Tab. Syst. 38 ; Hist. pi. 1, A, f. 7, 



no descr. 

 Caracolla helicoides, Lea, Trans. Am. Phil. Soc. IV, 103, pi. xv, f. 34 ; 



Obs. I, 113 (1834). 

 Helix caroliniensis, Lea, Trans. Am. Phil. Soc. IV, 108, pi. xv, f. 33 ; 



Obs. I, 112 (1834). 

 Xolotrema obstricta, Tryon, Am. Journ. Conch. Ill, 49, pi. ix, f. 3 (18(57). 



Ohio, Indiana, Tennessee, Georgia, South Carolina. 



H. obstricta differs from H. j^ciUiata in the following particu- 

 lars : The epidermis is free from " tuberculous prominences," but 

 has raised spiral lines between the costse on the upper and lower 

 surfaces of the shell. It has elevated, rigid, distant costas, the 

 whirls are subexserted and acutely carinated, the carina of the 

 upper whirls compressed, and overlapping the sutures as in H. 

 Cumberland iana. The umbilicus, as in the most carinated form 

 of H. palliata, is not always entirely covered by the reflected 

 peristome. 



Var. /3. — Whirls subexserted, carina less acute and prominent, 

 partially obsolete behind the aperture, not covering the sutures. 

 Greater diam. 24, lesser 19 ; height 8 mill. (5 whirls). Columbus, 

 Ga. This variety connects H. carolinensis with H. obstricta, and 

 is generally found in cabinets under the former name. 



Yar. y. — Whirls more convex, the last obtusely angulated in 

 front of, but very little behind the aperture. Greater diam. 21, 

 lesser IT ; height 7^ mill. (5 whirls). South Carolina. This is 

 the typical H. carolinensis, holding precisely the same relation 

 to H. obstricta, as H. palliata to H. palliata var. y. 



Helix appressa, Say. — Shell with the umbilicus covered, orbicu- 

 larly depressed, pellucid, with rib-like strije and minute revolving lines, 

 reddish horn-colored ; spire flattened ; whirls five, flattened above, the last 

 obtusely angular (the angle obsolete anteriorly) ; aperture oblique, com- 

 pressed, subtriangular ; peristome angularly broadly reflected, thickened 

 within, its terminations joined by a thin callus, on which is an obliquely 



