110 AMERICAN JOURNAL 



Belongs to the group of which H. ovum, VaL, H. rhea, Pfr., 

 and other well known large species are members. 



Named in honor of Capt. W. B. Chambertin, British Army. 



2. Ampelita {Helix) Bigsbyi, Tryon. — PL 10, fig. 3. 



Description. — Shell depressed trochiform, solid, acutely cari- 

 nate at the periphery ; whorls five, flat above, convex beneath, 

 with well impressed sutures. Surface marked by close slight 

 growth lines ; color chestnut, without bands ; aperture rhomboi- 

 dal, with white, thickened, reflected lip, partly covering the nar- 

 row umbilicus. 



Di7nensions. — Diam. 25, alt. 15, mill. 



Much resembles IT. unicolor, Pfr., but that species is some- 

 what larger, and the margin of the aperture is chocolate colored. 



Named after J. J. Bigsby, M.D., a zealous American natura- 

 list and collector. 



3. Orobia [Helix) Andamanensis, Tryon. — PI. 10, fig. 4. 



Description. — Shell depressed, thin above, thicker below, shin- 

 ing, with impressed sutures and growth lines ; spire but slightly 

 elevated ; whorls five, the last one slightly angulate at the peri- 

 phery, and more convex below ; aperture lunate ; lip simple, 

 acute, slightly reflected over the minute perforation. Light cor- 

 neous. 



Dimensions. — Diam. 12, alt. 6, mill. 



Resembles H. vitrinoides, Desh., but is a smaller species, with 

 one less whorl, more convex above, the sutures not margined, 

 and the strise of growth more distinct. 



Plectopylis {Helix) achatina, Gray. 



Somewhat smaller, but does not otherwise differ from Indian 

 examples, either externally or in its armature. 



4. Opeas {Bulimus) Pealei, Tryon. — PL 10, fig. 5. 



Description. — Shell turreted, elongate, slender, rather solid ; 

 whorls eight, flatly convex ; suture slight ; apex papillary ; aper- 

 ture ovate, small; lip simple; columella perpendicular, forming 

 an angle with the lip at the base. Light greenish horn color, 

 white within. 



Dimensions. — Length 35, diam. 9, mill. 



Resembles Bui. elongatulus, Pfr., but may be distinguished 



