Anculosai<: of tiif. Alabama River Drainage 35 



This species was collected by Mr. Smith at three localities, Jackson 

 Shoals, Eureka and two miles above the Coosa Paver, all the stations 

 being upon Choccolocco Creek and within Talladega County. There is only 

 slight variation in the material, though the shells taken at Eureka are 

 uniformly more slender than the Jackson Shoals specimens. In shell charac- 

 ters the adult mollusk is closer to A. taeniata Con, than to any other species, 

 but the two carinae on the whorls of the juveniles might seem to indicate a 

 relationship with A. ampla Anth. 



Six specimens of the type lot are smooth, shining, with only faint re- 

 volving striae ; 2 have well-marked revolving striae and are somewhat duller; 

 one has a fold 2 mm. below the suture, crossing low plicae and giving a 

 banded effect. A shell from Eureka has fine, erect lines from suture to 

 base, continuous and undulating. 



The banding arrangement consists of four lines, usually interrupted, these 

 showing more often in the epidermis than in the shell material of the aper- 

 ture. A single shell only has five bands. 



The columella is normally rounded, rather large ; in one old specimen it 

 is heavy and buttressed at the top as in Anculosae of the picta group. The 

 color of the columella varies from white to purple. 



The embryo shell is small, tightly coiled, the apex elevated. It consists 

 of about two whorls. The juvenile shell does not enlarge rapidly. It has 

 two well-defined carinae at the periphery, characteristic of the young of 

 A. praerosa Say, ligata Anth. and creek forms of ampla Anth. All the 

 juveniles have a weak columella. The four bands are made up of widely 

 spaced dots. A perfect adult would probably have five whorls. 



The operculum of this species is rather large in proportion to the size of 

 the shell as compared with opercula of other members of the taeniata group. 

 In paratypes, the left margin was found to be more curved than in the 

 operculum of the type. It seemed to be the tendency of most of the animals 

 to wear away the operculum against the columella at the thickened material 

 close to the nucleus. In only the one specimen could the spiral lines be 

 clearly traced. 



Anculosa brevispira H H. Smith, new species 



Fig. 12 



Shell: Subglobose, suggestive of A. ampla Anth. Longitudinal growth lines rather 

 fine, regularly spaced, crossed over part of the shell by discontinuous revolving lines. 

 Apex slightly eroded, flattened, the vifhorls developing with remarkable rapidity, this 

 expansion beginning immediately after the embryo whorls. Suture impressed. Body 

 whorl broadly shouldered, bearing four or five low nodules with spots of dark color- 

 ing matter between them. Peristome thin, flaring, nearly straight. Columella mod- 

 erately heavy, flattened nearly its whole length so as to give the inner edge a ridged 



