LATE CENOZOIC GASTROPODS 



21 



Original description: Nautilus, v. 35, p. 

 24, July 1921. 



"Shell differing from the other described 

 varieties of the tricarinate series in lacking 

 the carina on the periphery and base. Other- 

 wise similar. 



"Length, 3.5; width, 4.5; aperture length, 

 2.0; width, 1.8 mm. Topotype." 



Type locality: Near Morris, Grundy 

 County, Illinois. 



Collector: H. E. Culver, 1921. 



Age designation: Pleistocene, Late Wis- 

 consin. 



Remarks: Three paratypes, no. P929, are 

 in the ISGS collection. 



Vertigo gouldii loessensis Baker, 1928 

 Vertigo elatior loessensis (Baker) 



Plate 1, figure 2 



Holotype: Cat. no. P2366, ISGS. 



Original description: Nautilus, v. 41, p. 

 135, April 1928. 



"Shell differing from recent gouldii in be- 

 ing more ventricose, especially on the last 

 whorl, having the apical whorls wider and 

 more obtuse, the outer lip more auricled caus- 

 ing the aperture to have its longest diameter 

 more diagonal than in gouldii. There are 

 five denticles placed as in gouldii, but more 

 delicate than in the typical form; the palatal 

 denticles are long and subequal. 



"Length 2.0; diameter 1.3 mm. Holo- 

 type." 



Type locality: Three and a half miles 

 west and one and three-quarters miles south 

 of Lewistown, Fulton County, Illinois. 



Collector: H. R. Wanless, summer, 1927. 



Age designation: Pleistocene, Peorian 

 loess. 



Remarks: Two paratypes from the type 

 locality, no. P2366, are in the ISGS col- 

 lection; other paratypes, no. 145107, ANSP. 

 The ISGS collection contains numerous lots 

 from widespread localities in Illinois. 



Vertigo hibbardi Baker, 1938 

 Plate 1, figure 3 



Holotype: Cat. no. P6773, ISGS. 



Original description: Nautilus, v. 51, p. 

 126, April 1938. 



"The shell has 5 whorls and is very ven- 

 tricose over the body whorl. The sutures are 

 impressed, the apex is obtuse and bluntly 

 rounded. There is a conspicuous crest behind 

 the outer lip, behind which are two pits 

 showing the position of the palatal laminae. 

 The body whorl is flattened laterally and the 

 base of the shell is trumpet-shaped when 

 viewed from below. Base subumbilicate. Ap- 

 erture more than half the length of the last 

 whorl, the lips expanding outward. Outer 

 lip biarcuate. Lamella and plications 7 in 

 number. The angular and parietal lamellae 

 are long and extend some distance within the 

 aperture, the angular emerging further than 

 the parietal, the parietal curving spirally in- 

 ward toward the left. Columella or lamella 

 large and conspicuous, curving backward to- 

 ward the base of the shell. The lower palatal 

 fold is stout, nearly straight and somewhat 

 flattened on top. The upper palatal is stout, 

 high and lamellar and curves downward to- 

 ward the lower palatal. Both palatal folds 

 rest in front on a rounded callus and they ter- 

 minate abruptly at an equal distance within 

 the aperture and both increase in height as 

 they extend backward. There is a strong, 

 curved basal fold and a strong tubercular 

 suprapalatal fold. 



"Length 1.9; diameter 1.2 mm. Holo- 

 type." 



Type locality: Rexroad Ranch, SW 1 /^ sec. 

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

 Kansas. 



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

 mer, 1937. 



Age designation: Pleistocene, Late Ne- 

 braskan, Blanco formation. 



Remarks: The ISGS collection contains 

 a series of paratypes, no. P6773A; other 

 paratypes, no. 169883, ANSP. 



