[101] 



XX Diameter = 10 millimetres. 

 8 Dsedalochila tholus, W. G. Bioney. 



Plate 10, figures 7, 9. 



Shell solid, white, shining, ribbed above, smooth below : spire 

 depressed, conical, suture distinct ; whorls 7, convex, slightly 

 angular on the periphery ; umbilicus broad and shallow, about 

 half the diameter of the shell, showing 2| grooved whorls ; 

 aperture semi-oval, with a thickened, scarcely reflected lip 

 bearing one median and one basal tooth — both small, parietal 

 tooth large, rhomboidal. 



Diam, 11, height 4 mill. 



Texas. 



9. Dsedalochila Mooreana, W. G. Uinney. 



Plate 10, figure 8. 



Depressed, carinated, white, strongly striate above and nearly 

 smi'Oth beneath; spire somewhat raised, suture deep; whorls 6, 

 the last much deflexed at the aperture ; umbilicus narrower than 

 in JD. tholus, exhibiting 1^ whorls fully ; aperture semi-oval, lip 

 broad, heavy) but slightly reflected with two marginal teeth, of 

 which one is basal, and the other sub-basal, parietal tooth large, 

 rhomboidal. , 



Diam. 10, height 35 mill. 



Texas. 



It is questionable whether this and the forgoing are not varie- 

 ties of the same species. The only difference is in the narrower 

 umbilicus, broader lip and lower position of the lip- teeth in 

 Meer^ana. 



* 



* * 



Mexican Species. 

 10. Dsedalochila Behrii* Gabb. 



Plate 10, figures 40, 41, 43. 



Shell planorboid, coarsely ridged aboVe, striate below ; 

 whorls 5, quite convex, subangular at the periphery and very 

 much deflected and constricted behind the aperture ; umbilicus 

 broad with a minute central J»erforation ; aperture routided, the 



