192 CRETACEOUS TERIOD. 



Lispodesthes nuptialis White. 



Plate XVIII, fig. 3 a and h. 



Anclmra nuptialis White, 1874, Exp. & Suiv. west 100th Merid., Prelim. Rep. Invert. 

 Foss., 24. 



Shell small ; body subfusifoiin ; wing moderately large ; spire some- 

 what prominent, acute, but so thickly encrusted with callus that the volu- 

 tions are only obscurely shown, except where the callus is removed by 

 exfoliation; revolving angle absent or obsolete upon the volitions of the 

 spire, even when bared by exfoliation of the callus, but it is somewhat dis- 

 tinct upon the body-volution, being continued out upon the falciform pro- 

 cess of the wing. This posterior falciform process diverges widely from 

 the axis of the shell, but, by recurving, it extends nearly as far backward 

 as the apex of the spire ; anterior process of the wing somewhat thickened, 

 its breadth throughout about equal to that of the falciform process at the 

 base, its length and breadth about equal, its outer end obliquely rounded ; 

 space between the two processes very narrow ; from the base of the anterior 

 process the border of the wing extends forward with a concave curve to the 

 base of, and ends at, the long, slender anterior canal ; posterior border of the 

 wing concave and continuous with that of the falciform process on the one 

 hand, and with the callus-border of the posterior canal on the other. 



Length, from the apex of the spire to the end of the anterior canal, 

 twenty millimeters ; breadtli, measuring across from the base of the pro- 

 cesses of the wing to the opposite side, nine millimeters ; spire, falciform 

 process, and anterior canal, each about seven millimeters. 



Position and locality. — Strata of the Cretaceous period ; fifty miles north 

 of Camp Apache, five miles west of Mineral Spring, Arizona. 



Lispodesthes lingulifera White. 

 Plate XVIII, fig. 2 a and h. 



- Shell rather small ; body subfusiform ; Aving moderately large ; spire 

 of medium size, acute, nearly or wholly encrusted with callus, by which the 

 form of the volutions is obscured ; volutions six or seven, seen to be regu- 

 larly convex where the callus is exfoliated ; suture impi-essed ; revolving 



