Anculosae of the Alaiuma River Drainage 27 



Anculosa torrefacta H. H. Smith, new species 

 Fig. II 



Shell: Smaller than and not so heavy as the adult of A. tacniata Conrad, the 

 species to which it is most closely related. It is subglobose, subangulated, slightly 

 indented at the base. Lines of growth fine, close together, crossed by revolving striae, 

 usually wavy and not always continuous. Just below the suture to within eight or 

 ten millimetres of the peristome are low, broad nodules which are made to appear 

 larger than they are by reason of spots of dark pigment between them, these nodules 

 probably being the nearly obsolete remains of plicae. The type has no folds. The 

 body color of the shell is red-brown, rather dull, looking as if burned. It is broken 

 by four wide, continuous bands of purple. Apex eroded, the body whorl alone 

 remaining. Suture irregular. Peristome sharp-edged, slightly sinuous, a little curved 

 close to the suture. Columella smooth, regular, rounded, the callous not very heavy 

 for a shell of this size; it is colored with purple, this being lighter at the base of 

 the columella. Aperture ovate, reddish, marked with the four purple bands, one of 

 which is lighter in tone than the others. 



Operculum: Dark, reddish brown, thick ; altitude 8 mm., diameter 4 mm. ; the 

 whole leaf-like. The left margin is nearly straight, the apex acute, the right margin 

 firm, irregular; basal margin rounded. The polar point is small and at the base of 

 the left margin. Area of attachment elongate, rounded at base, apex acute; bordered 

 by a ridge of black callous. 



Measurements of type: Altitude, 16 mm.; diameter, 12 mm. Aperture — altitude, 

 12 mm. ; diameter, 7 mm. 



Type locality: Coosa River, Weduska Shoals, Shelby County, Alabama. Herbert 

 H. Smith, collector, August, 1913. 



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

 museum and in the Alabama Museum of Natural History. 



This species is apparently confined to the Weduska Shoals. It represents 

 an offshoot of A. taeniata and resembles to a degree the smooth forms of 

 A. griff ithiana Lea. Not all of the shells have the microscopic sculpture 

 of the type, though it is common to most. Shells w^ere found in the Smith 

 collection the early whorls of which were decidedly plicate and one speci- 

 men bore two waving, narrow folds at the shoulder and dim, very flat folds 

 on the base. A second specimen had widely spaced, nearly obsolete revolving 

 lines like the channels between the ribs of sulcate Anculosae. Forms much 

 constricted of body whorl were not uncommon. 



On old shells, the columella is nearly always eroded at the umbilicus. 

 Material with the columella white is rare ; in banded shells this character 

 is commonly purple, in unhanded specimens reddish. The curved peristome 

 is present in all the ligulate shells, common though not pronounced in others. 

 Specimens with straight lip are about one in four or five. 



Four equidistant bands are the prevailing banding arrangement, these 

 being usually broken into square or oblong markings. Shells with continu- 

 ous bands as in the type are about one in six. 



Torrefacta has a humped squat look and when numbers are laid out on a 

 table they remind one of pictures of Indians sitting at council with blank- 

 ets over their shoulders. 



The operculum varies somewhat, the lines of growth being sometimes 

 interupted by coarse lines representing the rest periods, the apex varying 

 from acute to rounded, the left margin being as often curved slightly as 

 straight. The right margin, particularly in young shells, is often torn, the 



