Anculosae of the Alabama River Drainage 55 



The columella is light for Anculosa. It is slightly angulatecl at the 

 center as in A. compacta Anth. It is sometimes porcelain white or bluish 

 white, more often stained pink or red. It was noticed in material from 

 Butting Ram Shoals that the shells with a white columella were old. The 

 lip is curved as in A. praerosa Say. This curved lip in the case of some 

 specimens gives the suggestion of the fissure of Gyrotoma. The peristome 

 is thin, firm, and in the instance of some old shells it is slightly thickened 

 with callous. The aperture is white, blue-white, reddish, and in some shells 

 yellowish. The color of ligata from near the mouth of Waxahatchee Creek 

 is chestnut brown; the Weduska Shoals shells, olive to dark brown; those 

 from The Bar, light to rusty brown. Anthony's shells were dark green. 

 This is a rare color among Mr. Smith's specimens. 



The nuclear whorls of ligata are raised, smooth, apparently consisting 

 of one and one-half whorls — the line between the embryo shell and the 

 following whorl being hard to make out. The suture is almost channelled 

 on the first two whorls of ligata. The typical "cross-hatch" sculpture 

 begins to show upon the third whorl. The periphery of most of the juvenile 

 shells is flattened. The extreme number of whorls of this species is prob- 

 ably five or six. 



The operculum is almost oval, dark brown, rather thick, leathery. Edges 

 of both left and right margins are thickened. Lines of growth are coarse, 

 those on the basal margin extending into four to seven stout, thorn-like 

 serrations, curving to the left. The polar point is deeply sunken and is 

 , located on the left margin close to the base. The spiral development is 

 obscure, but in one specimen examined the two whorls within the operculum 

 could be traced. 



The salient features of ligata are the constricted body whorl, the 

 textile-like microscopic sculpture and the hooked processes of the basal 

 margin of the operculum. 



Measurements: 



L 



8^ mm. Coosa River, Schowalter collection 

 «< II II i< 



« II II « 



Weduska Shoals, Shelby County 



(( n It a 



(i II II II 



Butting Ram Shoals, Coosa County 



The Bar, Chihon County 

 II II II i< 



•I II i< II 



Wetumpka, Elmore County 



