Ancul(JSAe of THiv Alaisama Rivkk Drainage 



33 



there being variations in the cur\'e of the margins and the position of the 

 polar point, the form of the apex and the extent of the wear and tear ex- 

 perienced. Perhaps a dozen oldriclii were found to have the produced oper- 

 cuhmi, noted in griffitliiaua. The normal operculum of the latter species is 

 larger than that of the species under discussion, as is also the operculum of 

 tacniata. There is, however, a clear resemblance in the opercula of the 

 three species, and coosacnsis may be included. 



Measurements of paralypcs: 



Anculosa flexuosa H. H. Smith, new species 

 Fig. 17. iS 



Shell: Sul)gloI)ose, rather heavy, surface broken with stout folds from suture to 

 base and having a half-dozen low, broad nodules at the shoulder which give a flat- 

 tened efifect to parts of the body whort. Apex flattened, partly eroded. Growth lines 

 tine, worn away ni places upon the tops of the folds. Suture impressed, irregular. 

 Aperture broadly ovate, bluish-white, the channels between the surface folds showing 

 through. Peristome a little curved below the suture, quite thin, slightly crenulate. 

 Cohunella of the type specimen deep purple, rounded, flattened on the surface from 

 the center nearly to the base. Color of shell, buckthorn brown. Within the aperture 

 appear a few spots of color, all that the type has of color bands or lines. 



Operculum: \'ery thin, reddish, translucent, small for so large an Anculosa. 

 Apex acute. Left margin lirm, nearly straight, curvmg abruptly to the apex. Right 

 margin thin, torn, broadly curved. Basal margin worn and broken. Growth lines 

 fine. The polar point is located at about where the left and basal margins meet. 

 Nearly two whorls may be made out within the operculum with the glass. The area 

 of attachment is narrow, elliptical, the deposit of dark callous on the edges being small. 



Mcasurcniciits : Altitude, 17 nun.; diameter, 13^ mm. Aperture — altitude, 10 

 mm. ; diameter, j}^ mm. 



'I xpe locality: Coosa River, Wetumpka. Elmore County, Alabama. Collected by 

 Herbert H. Smith, October, 1903. 



Type in the Museum of Zoology, University of Michigan ; paratypes in that 

 museum and the Alabama Museum of Natural History. 



This species, so far as known, is confined to the vicinity of Wetumpka 

 unless a somewhat puzzling shell more nearly conic, taken by Mr. Smith at 

 Duncan's Riffle, Chilton County, can be assigned to it. Specimens taken by 

 Schowalter, Call and T. II. Aldrich have been brought together in the Ala- 

 bama collection, indicating that while flexuosa is not exactly a common 

 mollusk it cannot be pronounced rare. Possibly it has been fairly widely 

 distributed as A. fonuosa or griffitliiaua by Dr. Schowalter, as individuals 

 have been found in some of Dr. Schowalter's boxes or trays which bear 

 these labels. 



Most of the material, like the type, is heavily folded. But a few spec- 



