AnCULOSAK of THlv Al^ABAMA RiVI-R DRAINAGE 



15 



The embryo shell is small, smooth, tightly coiled, the apex slightly raised. 

 It consists of about one and one-half whorls. The adult picta may possibly 

 acquire as many as six whorls. 



The ccbra forms of this species are unquestionably pathological. The 

 coloring matter has been deposited in somewhat zigzag method longitudin- 

 ally, four or five of these "blotches" occuring on the whorl. This irregular- 

 ity in instances takes place in connection with the normal banding system. 

 The abnormality has been noted in other species. Anthony's description 

 and the remarks of Tryon lead to the assumption that picta was the shell 

 before Anthony when he established the species zebra. 



Selma 



The operculum of picta is large, leaf-like, rather thin, reddish-brown, 

 and consists of about three whorls. The left margin is thickened and usual- 

 ly straight, the apex acute, the right margin thin and frayed, the basal 

 margin broadly rounded. The polar point is slightly sunken, the edges of 

 the whorls within the operculum being sharply marked and raised though 

 more so in some opercula than in others. The nucleus is well within the 

 body of the operculum, slightly nearer the left than the right margin and 

 situated about the lower third of the length. A "freak'' operculum shows 

 four well defined whorls. Growth lines are coarse. 



'Mr. Smith's Coosa River picta are labeled Wetumpka, but in a letter 

 to Dr. Walker he has explained that the species was not taken in the true 

 Wetumpka Shoals, but on gravel bars of the river below the town, a section 

 geologically much younger. The other extreme of distribution, so far as 

 known, is Clairborne. 



Ancidosa jormosa Lea 

 Fig- 3 



Anculosa formosa Lea, Proc. Acad. Nat. Sci., Phila., i860, p. 187; Obs. ix, p. '/6, 

 pi. 35, fig. 61. 



Lea described specimens apparently of unusual rotundity and figured a 

 juvenile individual. Tryon does not seem to have had access to a large 



