GONIOBASIS. 145 



basis) Hydei, Con., but that is conical, having a high granular spire. 

 I name this after my friend Thomas Stewardson, M.D., to -whom I 

 am indebted for many fine specimens of our Southern mollusca. — Lea. 



I at first considered this shell the young of ccdatura, but 

 have finally concluded that it is distinct. The surface is 

 ridged around, the ridges being fretted, disposing to tuber- 

 culation ; the shell is very solid and generally dark green and 

 polished. A figure of the adult satisfactorily exhibits the dif- 

 ferences between it and ccelatura. 



7. G. flavescens, Lea. 



Goniobasis flavescens, Lea, Proc. Acad. Nat. Sci., p. 271, 1863. Jour. Acad. Nat. 

 Sci., V, pt. 3, p. 339, t. 38, f. 202, March, 18G3. Obs. ix, p.- IGl. 



Description. — Shell striate, sometimes granulate and folded, subcy- 



lindrical, yellowish, thick ; spire obtusely conical ; sutures irregularly 



impressed ; whorls slightly convex, the last very large ; 



•^ " ' rig.269. 



aperture large, subrhomboidal, banded or white within; 



outer lip sharp, scarcely sinuous ; columella bent in, very 



much thickened above and twisted. 



Operculum ovate, rather thick, brown, with the polar 

 point near the left margin above the base. 



Habitat. — Oconee and Tennessee Rivers, Tennessee; '^^^ 

 Rev. G. White. 



Diameter, -43 ; length -97 inch. 



Observations. — Quite a number of specimens were sent to me by 

 Mr. White, and among them there is great variation. They are allied 

 on one side to Tryoniana, herein described, and on the other to Mela- 

 nia (Goniobasis) brevis (nobis.) It is a larger species than the latter, 

 and smaller and more cylindrical than the former. Brown bands 

 are more or less observable in the interior of about half the speci- 

 mens before me. The callus above is usually thick and often 

 colored. One specimen only is entirely brown inside. The aperture 

 is more than one-third the length of the shell, none have the apes 

 sufficiently perfect to ascertain the number of whorls. There are 

 probably about six. There is a close affinity between this and Mcla- 

 nia (^Goniobasis) Holstonia (nobis), which, however, is more robust, 

 of a different color and more granulate. — Lea. 



L. F. W. S. IV. 10 



