LATE CENOZOIC GASTROPODS 



19 



etal lamella penetrates within the aperture 

 more than three-fourths of a whorl. Half a 

 whorl within the aperture there is a short, 

 stout lamella on the axis. There are five 

 baso-parietal folds, the first two basal folds 

 are large and heavy, the first kidney-shaped, 

 the second larger and lamellar, erect. The 

 other three folds are low, rather long and 

 curved. All basal folds are arranged radially. 

 Height, 2.0; diameter, 2.7 mm. Holotype." 



Type locality: Rexroad Ranch, SWV4 

 sec. 22, T. 33 S., R. 29 W., Meade County, 

 Kansas. 



Collector: C. W. Hibbard and party, sum- 

 mer, 1937. 



Age designation: Pleistocene, late Nebras- 

 kan in Blanco formation. 



Remarks: Fifty paratypes, from the type 

 locality and bearing the same number as the 

 holotype, are in the ISGS collection; other 

 paratypes, no. 169886, ANSP. This species 

 is a common fossil in Nebraskan and Kansan 

 deposits in the central Great Plains region. 



Succinea grosvenorii gelida Baker, 1927 

 Plate 1, figure 13 



Holotype: Cat. no. P875A, ISGS. 



Original description: Nautilus, v. 40, p. 

 118, April 1927. 



"Shell small, elongated, rather narrow; 

 whorls 3% convex, separated by deep su- 

 tures, last whorl comparatively small, flat- 

 sided, or but slightly convex; spire long, 

 acute; aperture rounded, about half as long 

 as shell; columella straight curving into the 

 parietal wall in a gentle curve, not forming 

 a distinct angle ; there is a slight callus which 

 is spread over the parietal wall; sculpture 

 of rather fine, vertical striae." 



Length, 8.0; diameter, 4.2; aperture 

 length, 4.0; diameter, 2.4 mm. Type. (Bak- 

 er's measurements.) 



Type locality: One-half mile northwest 

 of railway depot, Irene, Boone County, Illi- 

 nois. 



Collector: M. M. Leighton, 1920. 



Age designation: Pleistocene, Peorian 

 loess. 



Remarks: Three paratypes from the type 

 locality are in the ISGS collection; other 

 paratypes, no. 142712, ANSP. Shells iden- 

 tified by Baker as S. g. gelida occur commonly 

 in the loesses of Illinois. 



Succinea ovalis pleistocenica Baker, 

 1927 



Plate 1, figure 11 



Holotype: Cat. no. P2088A, ISGS. 



Original description: Nautilus, v. 40, p. 

 117, April 1927. 



"Shells differing from typical ovalis in 

 having a rounder aperture and compara- 

 tively longer spire; it averages somewhat 

 smaller than the ovalis now living in Illi- 

 nois." 



Length, 19.0; diameter, 11.5; aperture 

 length, 11.5; aperture diameter, 8.0 mm. 

 Holotype. (Baker's measurements.) 



Type locality: Three miles southwest of 

 Marshall, Clark County, Illinois. 



Collector: Paul MacClintock, 30 August 

 1925. 



Age designation: Pleistocene, Yarmouth 

 loess. 



Remarks: The ISGS collection contains 

 four paratypical specimens, no. P2088A, from 

 the type locality; other paratypes, no. 142710, 

 ANSP. The ISGS collection contains nu- 

 merous lots from Pleistocene deposits of Illi- 

 nois, identified by Baker as S. 0. pleistocenica. 



Succinea retusa fultonensis Baker, 



1928 



Oxyloma decampi fultonensis (Baker) 



Plate 1, figure 12 



Holotype: Cat. no. P2368, ISGS. 



Original description: Nautilus, v. 41, p. 

 136, April 1928. 



"Shell elongately ovate, compressed, spire 

 long, conic, sutures well impressed ; whorls 

 three, somewhat oblique, narrow, the second 

 whorl much swollen as compared with the 

 first whorl which appears above the second 

 whorl as a small knob; aperture narrow, 

 ovate, narrowed above, widely rounded be- 

 low; columella somewhat incurved. 



