45 Calvin Goodrich 



collected by Call at the same place are about a half-dozen more shells of 

 the same form. The locality seems to argue that these Wetumpka shells are 

 depauperate forms of griffithiana Lea, and doubtless they are when one con- 

 siders the appparently restricted habitat of the shozvalterii group. The 

 question illustrates the variability of the Coosa River Pleuroceridae and the 

 tendency of each species to develop forms resembling other species in the 

 same locality. 



In sculpture, all of the material is very much alike. The Three Island 

 Shoals specimens differ in having larger folds or ribs than the Fort William 

 Shoals specimens, these being also more widely spaced. One of the shells 

 from Fort William Shoals is lighter in color than the type, one darker. 

 One is without bands in the aperture, the other has bands which are in- 

 terrupted, following the sides of the folds. The banding arrangement in 

 the Three Island Shoals shells are after this pattern rather than that of 

 the type. 



Measurements: 



Anculosa sulcata H. H. Smith, new species 



Fig. 20 



Shell: Rather heavy, subglobose, nearly as wide as it is high, slightly angled at 

 the periphery and indented a little in the base, resembling A. grifHthiana Lea in this 

 regard. The type has fifteen strong, narrow ribs of varying size from suture to base. 

 The first two rilas of the body whorl are at right angles to the whorl preceding, giving 

 a decided shouldered effect to the shell. The large body whorl is covered with fine 

 growth lines and these are crossed at places by revolving lines more or less undulate. 

 Color light brown, shining. Three continuous bands show within the aperture, the 

 uppermost being heavier than the other two. Apex eroded, only two whorls remain- 

 ing. Suture irregularly impressed, almost channeled where the first rib of the body 

 whorl rises above it. Peristome slightly curved, crenulate. Columella porcelain white, 

 smooth, rounded, not so heavy as in several species of equal size. Aperture ovate, 

 yellowish-white, translucent. The aperture is smooth to within one or two mm. of 

 the peristome, thereafter furrowed. 



Operculum: Dark, thin, in size 8^ mm. by 4J^ mm. Apex rounded. The left 

 margin is firm, the right margin fragile. Lines of growth fine. Polar point is close 

 to the base of the left margin. Whorls three, the spiral lines loosely coiled. The area 

 of attachment is long and narrow. 



Measurements: Altitude, i9J4 nim. ; diameter, i^Yi mm. Aperture — altitude, 14^ 

 mm. : diameter, 7^ mm. 



Type locality : Coosa River, Ten Island Shoals, St. Glair County, Alabama. Col- 

 lected by Herbert H. Smith, October, 1914. 



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

 museum and the Alabama Museum of Natural History. 



The species is apparently confined to the stretch of the Coosa River 



