i6 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



[vol. 50 



evenly disposed, prominent but hardly nodulous at the intersections, 

 forming with the ribs a coarse, rather regular reticulum ; spire short, 

 conic ; suture appressed ; the whole shell in the fully adult stage with 

 a very thin coat of enamel ; outer lip thin, expanded, slightly re- 

 flected; more or less denticulate at the extreme margin. Lon. of 

 shell, 143 ; of aperture, 103 ; max. diam., 44 mm. 



Ripley horizon of Upper Cretaceous at Kaufman, Texas (U. S. 

 N. M., 20,996) ; collected by Dr. T. W. Stanton, U. S. Geological 

 Survey. 



This has somewhat the aspect of V . eufaulensis, but the spire is 

 shorter and more blunt, the maximum diameter is more posterior, 

 the sculpture is much more distinct and regular, the brilliant polish 

 is wanting, and the substance of the shell has a peculiar brownish 

 tint and subtranslucent character, which is probably not entirely due 

 to conditions of fossilization. 



VOLUTOMORPHA DUMASENSIS Dall, n. sp. 



(Figure 4) 



Fig. 3.— V. retifera Dall. ///. Side 

 view of fragment, showing mold of 

 recurved posterior sinus. 



Fig. 4. — V. dumasensis Dall. 1/1. 

 Fragment, showing character of 

 spire and shallow posterior sinus. 



Specimens all imperfect, but showing one strong and one obsoles- 

 cent plait ; penultimate whorl with thirteen short riblike swellings at 

 the periphery, weaker in front and absent behind, where there is a 

 wide shallow constriction of the whorl extending from the periphery 



