4 University of Michigan 



with the older species in shell characters, but also in the matter of 

 the operculum. 



Goniobasis microlineata, new species 



Description: Shell elongate, acuminate, color uniformly 

 greenish brown, shining, smooth, without bands or other color 

 markings except the usual light line at the sutures, more or less 

 common to the genus. Sutures not deeply impressed, but appear- 

 ing somewhat V-shaped or angulated under the glass. Apex of 

 type eroded. Whorls only slightly convex, the two uppermost 

 being more nearly flat than the others. Lines of growth fine, 

 regular except at the rest periods. Many spiral lines occur upon 

 the immature whorls, but are absent on the body whorl. Where 

 these lines and the lines of growth cross a light, reticulated appear- 

 ance is given to the shell under the glass. Aperture ovate, less 

 than one-half the total height of the shell, pearl white within. 

 Columella white, rather heavy for so small a shell. Peristome 

 somewhat sinuous, edged with black. 



Operculum ovate, thin, translucent, reddish brown. Apex 

 acute. Growth lines very fine, regularly spaced. Left margin 

 slightly thickened, right margin thin, torn. The nucleus is sunken, 

 and is located close to the base, nearer to the left margin than to 

 the right. The spiral lines are rather obscure, but the operculum 

 apparently consists of three whorls. The area of attachment is 

 elliptical, and is bordered with thick, reddish callus. 



Measurements: Altitude, 14^ mm.; diameter, 6| mm. Aper- 

 ture altitude, 6 mm. 



Type locality: Rough Creek, Falls of the Rough, Grayson 

 County, Kentucky. Collected July 24, 191 7. 



Type: No. 10584, Museum of Zoology, University of Michigan. 



Remarks: An uneroded shell has apical whorls carinated at 

 the base. Shells the epidermis of which has been removed are of 

 a dull flesh color, a few of them bluish. There are no color mark- 



