Anculosau of the Alabama River Drainage 49 



The sculpture is confined to the fine growth Hues and occasional indicat- 

 ions of revolving striae. Color varies from yellow to dark brown. In many 

 of the shells the bands are so dark and broad that the ground color of the 

 epidermis shows only as narrow lines. The bands are continuous or interrup- 

 ted, the formula of four equidistant bands prevailing. Of 125 specimens 

 in one lot from the Higgin's Ferry locality, 1 1 1 had the four bands ; 2 had 

 five bands; 7 had modified arrangements of the four-banded formula; 5 were 

 without bands. No variation was observed as between localities. 



The flattening of the columella was more pronounced in the material 

 from the type lot than in most of the other shells. This, however, is a 

 fairly constant characteristic and is so marked in some specimens as to 

 give them an excavated appearance, this being occasionally heightened 

 by the erosion of the body whorl over the umbilical region. The color of 

 the columella is usually purple, though white is not uncommon. The peris- 

 tome sometimes has a slight curve close to the suture. 



The embryo occnlfata is very small, the apex raised or flattened, loosely 

 coiled, smooth, consisting of one and one-half whorls. In many of the 

 juveniles the peristome is raised at the top above the plane of the apex 

 and the bulk of the shell matter is so crowded into the upper half that 

 the lower half of the shell is made up mostly of a thin columella and a 

 flaring outer lip. This last character is suggestive of Neoplanorbis smithi 

 Walker. 



Measurements: 



Melania compacia Anth., Annals N. Y. Lyceum Nat. Hist., Vol. VI, p. 123, pi. iii, 

 fig. 22, April, 1854. 



Lithasia nucha Lea, Proc. Acad. Nat. Sci., Phila., XII, p. 188, i860. 



A note by Mr. Smith among his labels reads: "This is the M. coinpacta 

 Anth., Lithasia nuclea Lea, Lithasia compacta of Tryon and later authors. 

 Certainly not a Lithasia, and that genus has not been found in the Alabama 

 drainage, though several species are incorrectly referred to it. I think 

 that compacta is an Anculosa, allied to A. znttata Lea. A variety or closely 

 allied species lives in the Warrior." 



The judgment of Mr. Smith appears sound. Lea in his description of 

 nuclea notes the similarity to Anculosa. It is strange that Tryon should 

 have recognized compacta as a Lithasia while placing the allied mclanoides 

 Conrad of the Black Warrior among the Anculosae. 



