OF CONCHOLOGY. 171 



3. TJiaumastus excelsus, Gould. 



Plate 13, figure 10. 



Elongate ovate, acuminate, somewhat solid, smooth; spire 

 elevated, acute ; whorls 7, the last two-thirds the total length ; 

 aperture small sub-ovate, lip reflexed, columellar margin much 

 expanded, lip extremities joined by a slight callus ; axis rimate. 

 Fulvous with white strigations, lip white. 



Length 44, diam. 19 mill. 



Lower California. 



4. Thaumastus patriarcha, W. G. Blnney. 



Plate 13, figure 15. 



Shell ovate, perforate, solid, rugosely striate ; whorls 6, con- 

 vex, the last ventricose and two-thirds of the total length ; 

 aperture ovate, lip thickened within, and its extremities joined 

 by a heavy white callus, columellar margin slightly reflected 

 over the umbilicus. White. 



Length 35, diam. 19 mill. 



Texas and Mexico. 



Larger and more rugose than the allied species. 



5. Thaumastus alternatus, Say. 



Plate 13, figure 16. 

 Plate 14, figures 10, 12. 



Ovate-conic, rather thick, umbilicated ; suture slightly im- 

 pressed ; whorls 6, lip simple, expanded, thickened within, 

 columellar margin reflected. White, yellowish or grey, with 

 brown oblique longitudinal irregular or jagged bands, sometimes 

 confluent. 



Length 30, diam. 17 mill. 



Texas and Mexico. 



Fig. 16 represents the typical form, and fig. 12 a not quite 

 adult, highly colored form ; fig. 10 is a small and more numer- 

 ous variety, if it be not indeed specifically distinct, It is the 

 shell described by Menke as Bulimus lactarius. 



