18 



ILLINOIS STATE GEOLOGICAL SURVEY 



Original description: Nautilus, v. 40, p. 

 120, April 1927. 



"Shell elongated, turreted, scalariform ; 

 spire long, scalar; sutures deeply impressed; 

 whorls about 8, very convex, the body whorl 

 disproportionately larger than the preceding 

 whorl; umbicilus round, wide, deep; aper- 

 ture roundly oval, peristome thin, continu- 

 ous, the inner lip forming a rounded, erect 

 border near the umbilicus." 



Length, 7.8; diameter, 3.5; aperture 

 length, 2.1; diameter, 1.6 mm. Type. (Bak- 

 er's measurements.) 



Type locality: New Harmony, Posey 

 County, Indiana. 



Collector: L. E. Daniels; from A. A. 

 Hinkley collection. 



Age designation: Pleistocene, Peorian 

 loess. 



Remarks: The ISGS collection contains 

 two paratypes from the type locality and 

 bearing the same number as the type; other 

 paratypes, no. 142713, ANSP. P. scalaris 

 occurs widely in Pleistocene deposits of Illi- 

 nois. 



Stenotrema hubrichti Pilsbry, 1940 

 Plate 4, figures 14-16 



Paratype: Cat. no. P5137, ISGS. 



Original description: Pilsbry, Land Mol- 

 lusca North America, v. 1, pt. 2, p. 687, fig. 

 423, 1940. 



"The imperforate shell is depressed, lens- 

 shaped, acutely carinate, the height not 

 much exceeding half of the diameter. Spire 

 low conic, of slowly increasing whorls, the 

 first convex, the rest nearly flat, impressed 

 above the keel; last whorl descending in 

 front. The base is flattened below the keel, 

 then convex, and slightly impressed around 

 the central axis. The embryonic whorls are 

 most minutely granulose. Later whorls are 

 lightly striate, the striae low, very unequal. 

 Base with fainter striae and densely, mi- 

 nutely granulose. The aperture resembles 

 that of S. fraternum but is narrower, the 

 parietal tooth nearer to the basal lip, ap- 

 proaching it slightly towards the outer end ; 

 nearly straight, rather low, connecting with 

 the end of the columellar lip by a low, curved 



ridge. The basal lip is reflected, rather 

 strongly thickened within, the thickening 

 narrowing at the passage of basal into col- 

 umellar margin, forming a rounded sinus 

 there; in the outer half of the basal margin 

 it is wider, but narrows gradually at the po- 

 sition of the keel, not abruptly as in S. bar- 

 big erum." 



Height, 4.4 mm.; diameter, 9.9 mm.; 5Vi 

 whorls. (Measurements mine.) 



Type locality: Pleistocene "talus" just 

 south of McCann School, two miles north- 

 east of Aldridge, Union County, Illinois. 



Collector: Leslie Hubricht. 



Age designation: Pleistocene. 



Remarks: The holotype and a series of 

 paratypes, both numbered 174941, are in the 

 ANSP collection. The shells in the ISGS 

 collection are from a paratypical series from 

 the private collection of Leslie Hubricht, 

 no. A5137. 



This unusual species, described by Pilsbry 

 from Pleistocene loess deposits in Illinois, is 

 included for the sake of completing the list 

 of types of late Cenozoic mollusks in the 

 ISGS collections. 



Strobilops sparsicostata Baker, 1938 

 Plate 1, figures 4-6 



Holotype: Cat. no. P6774, ISGS. 



Original description: Nautilus, v. 51, p. 

 127, April 1938. 



"Shell broadly conic with somewhat ele- 

 vated, dome-shaped spire. Whorls 5i/2> the 

 first 1% smooth, the balance sculptured with 

 distinct ribs, widely spaced, with frequently 

 a faint riblet between. The umbilicus is 

 contained about seven times in the diameter 

 of the shell. Last whorl decidedly angular, 

 the base of the shell smooth or with occa- 

 sional faint riblets extending over it from 

 the dorsal surface. Aperture with expanded, 

 thickened peristome and a heavy palatal 

 callus. There is a very heavy parietal lamella 

 emerging from the edge of the callus and a 

 weak infraparietal lamella which emerges 

 within the aperture almost to the parietal 

 callus in some specimens. This is often not 

 developed outside of the aperture. The pari- 



