14 AMERICAN JOURNAL 



MONOGRAPH OF THE FAMILY STREPOMATIDJ3. 



[ Continued from p. 341, Vol. I.] 



I x BY GEORGE W. TRYON, JR. 



GONIOBASIS, Lea. 

 a. Shell spirally ridged. 



1. G. procissa, Anth. Fig. 1. Ovate, thick, inflated; 

 spire short, conical ; whorls 5, convex, the last large, with five 

 sharp, raised revolving carinas, the two central ones more 

 prominent ; aperture small, round-ovate. Greenish or brown- 

 ish. N. Gar. 



b. Shell tuherculate or nodulous. 



2. G. varians, Lea. Figs. 2, 3. Cylindrically conical; 

 smooth, plicate or striate, thick ; spire raised, suture impressed ; 

 Avhorls 7, shouldered, and frequently tuberculate; aperture 

 small, elliptical, narrow at base. Yellowish or brownish, 

 sometimes banded. Coosa River, Ala. 



3. G. Hydeii, Gonr. Fig. 4. Elevated, conical ; spire ele- 

 vated, suture slight^ impressed; whorls about 7, flattened, 

 the last rounded below the periphery, with three or four acute 

 spiral lines of tubercles on the upper portion of the whorl, 

 and one or two rows on the spire ; aperture elliptical. Brown- 

 ish, sometimes with green bands. Black Warrior River, Ala. 



4. G. decorata, Anth. Figs. 5, 6, 7. Sub-fusiform ; spire 

 elevated, suture impressed ; whorls 6, last very large, covered 

 with transverse rows of tubercles, the lines towards the base 

 less tuberculate ; aperture large, rhomboidal. Yellowish or 

 dark brown, frequently with several dark bands. Geo. and 

 E. Tenn. 



Fig. 5 represents O. decorata, Anth., the young shell; Fig. 6 is O. gra- 

 nata, Lea, a half-grown shell, and Fig. 7 is G. Tryoniana, Lea, the adult. 



5. G. caelatura, Gonr. Fig. 8. Sub-fusiform ; spire ob- 

 tusely elevated, suture impressed ; whorls 6, slightly convex, 

 the last large, with obscure longitudinal ribs, and numerous 

 unequal, prominent revolving lines, sub-nodulous where they 

 cross the ribs ; aperture rather large, oval. Reddish brown, 

 sometimes banded. Geo. 



Narrowpr, with closer stria, and not so tuberculate as decorata. 



