26 University of Texas Bulletin 



PLATE IV 



Fig. 1, Turritella georgetownensis n. sp., natural size, 



Fig. 2, Turritella georgetownensis n. sp., X2. 



Fig. 3, Turritella austinensis n. sp., natural size. 



Fig. 4, Turritella austinensis n. sp., X2. 



Fig. 5, Turritella bonnellensis n. sp., natural size. 



Fig. 6, Turritella bonnellensis n. sp., X3. 



Fig. 7, Turritella planilateris Conrad, natural size. 



Fig. 8, Turritella mabriensis n. sp., natural size. 



