Anculosak of the Alabama Rixkr Drainagr 17 



columella purple, 4 were of red and i black. Uelow Peckerwood Shoab, 

 which are an extension of those of Fort William, purple becomes the pre- 

 vailing color of the columella, with the exception that the formosa taken 

 by Mr. White at Wetumpka had the columella white. 



In this species there occur specimens with a ground color of red, show- 

 ing most richly in the columella. One shell from Fort William Shoals is 

 black throughout, or a vei^ dark purple. Material of the flamuiata colora- 

 tion appears in lots from Hall's Island, Talladega County, down. 



The embryo shell of formosa is smooth, tightly coiled, the apex slightly 

 elevated. It consists of one and one half to one and three-quarters whorls. 

 Probably an adult specimen, if uneroded, would show six whorls. 



Two lots of shells in the Alabama collection, four specimens in all, are 

 labeled as from the Cahaba and Alabama rivers. It is to be suspected that 

 these are cases of mislabeling. Mr. Smith's collecting justifies the belief 

 that \A'etumpka is the southernmost point of distribution. 



The operculum is thin, wing-like, dark-red. Left margin firm, nearly 

 straight and slightly bent backward at the acute apex ; right margin broadly 

 curved, very much torn ; basal margin rounded. Growth wrinkles very 

 coarse. The nucleus is located in the lower third of the .operculum about 

 I mm. from the left margin. Whorls three. Spiral lines raised, not always 

 well defined or regular. The area of attachment is elliptical, narrow relative 

 to the size of the operculum. The operculum of formosa shows a close 

 affinity to that of picta. 



Measurements of Shells: 



Altitude Diameter 



lyVz mm. 13 mm. Below Minnesota Bend, Etowah County 



19 13 Ten Island Shoals, St. Clair County 

 17^/4 13^ 



16 12 " " " " " " 



16V2 12 Lonigan Shoals, " " " 



i8,'/2 . 12^ Clarence Shoals, '' 



18 13 P'omby Shoals, " " " 



20 135^2 Truss Shoals, " " " 

 18 14 Hall's Island. Talladega County 



21 l^Yz Three Island Shoals, Talladega County 

 ig 12 " " " " " 

 24 14 Ft. William Shoals, "' " 

 20 13 " " " " " 

 ig'A J3V2 



16 12 



14 11'^ 



19I/2 14 Peckerwood Shoals, " " 



ig 13 Weduska Shoals, Shelby County 



19I/2 14 The Bar, Chilton County 



18 12V2 



20 14 Butting Ram Shoals, Coosa County 



19 I3J4 



15^ 12 Wetumpka. Elmore County 



