36 Calvin Goodrich 



effect; color white, touched with red-brown on the outer edge close to the epidermis. 

 Aperture broadly ovate, reddish, having four interrupted, equidistant bands about 1 

 mm. in width. Color of shell buckthorn brown. 



Operctilwn: Dark red, somewhat thin, in shape like a minute willow leaf; more 

 narrow in proportion to length than the operculum of A. taeniata Conrad. Growth 

 lines are well marked, but not particularly heavy. Left margin nearly straight, right 

 margin curved, firm ; basal margin liroadly rounded, worn. Apex slightly rounded. 

 The polar point is on the left margin close to the base. No trace of the spiral lines 

 can be discovered under the glass. The area of attachment occupies slightly more 

 than half the posterior surface, being elliptical, edged with dark callous. 



Measurements: Altitude, \},Y2 mm.; diameter, 10^ mm. Aperture — altitude, 7^ 

 mm. ; diameter, 5^ mm. 



Type locality: Fort William Shoals, Coosa River, Talladega County, Alabama. 

 Collected by Herbert H. Smith, June, 1914. 



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

 museum and the Alabama Museum of Natural History. 



This species varies greatly in form, most specimens having the character- 

 istically expanded aperture, but many being as conic as griffithlana Lea 

 or taeniata Conrad. The young do not closely resemble the adults, the mature 

 characters developing with about the third whorl. The peristome of the 

 juvenile shell is not flaring; it curves at the suture over the early deposit of 

 columellar callous. The upper part of the whorl is more shouldered than in 

 most of the old shells. The affinities of hrci'ispira are somewhat obscure, 

 but the impression given during the study of the species is that it is near 

 to taeniata. 



Numbers of the specimens are folded or slightly ribbed. Occasional 

 specimens bear nodules at the top of the body whorl which may indicate 

 descent from a plicate state. In one lot, 9 individuals have folds from suture 

 to base which vary in strength; 19 have folds at the shoulder only; 59 are 

 entirely smooth. 



The color of the epidermis ranges from snufif brown to sepia and a few 

 specimens have the dark mottled appearance of some A. slwzvalterii Lea. 

 The bands are usually four in number, continuous or broken. Three vari- 

 ations of the banding arrangement froiu the normal formula were observed, 

 and each lot collected by Mr. Smith contains shells without bands. 



The columella, flattened and a little angular rather than curved, seems to 

 be one of the most definite characters of this race. The lower outer edge is 

 not raised so distinctly above the "abutting"' epidermis as in the case of 

 ampla. The color of the columella is usually purple. In some it is white 

 and in many specimens it is splotched with i)urple or red, the ground color 

 being white or pink. 



The embryo shell is minute, one and one-half whorls in size, the apex a 

 little raised. The second whorl when coiupleted is very large as compared 

 with the nuclear section. An adult probably has four whorls. 



One doubtful specimen of brevispira was taken at Three Island Shoals. 

 The species appears to be exceedingly common on parts of Fort William 

 Shoals. It was not found apparently from there down the river until The 

 Bar and Duncan's Rififle in Chilton County were reached, though doubtless 

 it does exist at favorable stations between these shoals. Lower river speci- 



