14 Calvix Goodrich 



COM PACTA GROUP 



A. compacta Anth. Cahaba River and tributaries. 



A. mclanoidcs Conrad. Black Warrior River and possibly Alabama 

 River. 



A. z'ittata Lea. Coosa River. The Bar, Chilton County, to Wetumpka. 



LIGATA GROUP 



A. ligata Anth. Coosa River, Weduska Shoals, Shelby County , to 

 \\'etumpka. 



Anculosa picta Conrad 

 Figs. 6, 7 



.litciilosa picta Conrad. Silliiiiaii's Journal. \'ol. ii, p. 342, pi. i, fig. 15, Jan., 103^. 

 Anculosa zebra Anth., Proc. Acad. Xaf. .Sci.. Phil, Feb., i860, p. 69. 



The species is described by Conrad from specimens he collected in the 

 Alabama River at Clairborne, this material, according to Tryon, consisting 

 of stunted or immature forms. Tryon probably had reference to a modi- 

 fication very common to the species in the Alabama River at Selma and less 

 marked in the Coosa, occuring besides in at least one other member of this 

 group. The normal picta is subglobose to conic, with areas almost flatten- 

 ed, having obscure nodules at the shoulders or in instances distinct nodules, 

 the aperture large, ovate. In the case of the modification, the shell is de- 

 cidedly narrow in relation to altitude,, the whorl smooth and rounded, curious- 

 ly compressed on the side close to the peristome, the aperture almost round. 



The growth lines of picta are ordinarily fine, sometimes almost obliter- 

 ated as if from the scouring by sand. Revolving striae are usually very faint 

 and discontinuous, and often entirely absent. Folds, where they occur, are 

 not very prominent. In one lot of Mr. Smith's own collecting from the 

 Coosa at Wetumpka. 6 specimens had well-marked folds from suture to 

 base, 3 had folds faint or nearly miscroscopic, 4 were without such mark- 

 ings ; 6 had knobs or plicae at the shoulder, 7 were without such sculpture. 



In color this species is usually a shining, light brown, varying to dark 

 brown, sometimes greenish. The bands are fine, close-set lines of coloring 

 matter, interrupted or continuous, varying in number from four or five to 

 fifteen or sixteen. In several of the lots, the unhanded shells are equal in 

 number to those with bands. 



In half-grown specimens, the columella is strong, smoothly rounded, the 

 deposit of callous at the top not particularly heavy. This character in old 

 specimens shows a tendency to distortion ; the columella becomes flattened on 

 the outer edge and often is there eroded; the deposit of callous at the junc- 

 tion with the peristome is so large as to give an effect of buttressing peri- 

 stome and columella. Of 27 shells in qne lot from Wetumpka, the columella 

 of all except one was white. A Cahaba River lot had 6 shells with white and 

 7 with reddish columella. White, purple and reddish columellae were noted 

 in Alabama River .shells. The peristome of picta is .sharp-edged, firm, usual- 

 ly straight, sometimes curved near the suture. 



