LATE CENOZOIC GASTROPODS 



17 



"Shell differing from typical multiline at a 

 in being larger, the whorls more gibbous, the 

 spire more depressed, and the sutures be 

 tween the later whorls more deeply im- 

 pressed ; the last whorl begins to rapidly de- 

 scend on the previous whorl until the upper 

 part of the outer lip rests against the periph- 

 ery, instead of above this point, as in multi- 

 lineata; the deflection of the upper part of 

 the whorl toward the aperture is also more 

 abrupt, and forms a distinct shoulder at this 

 point; the reflected lip is much heavier as is 

 also the umbilical callus; the spiral color 

 bands and lines are apparently much less 

 numerous than in typical multiline ata. 



"Greatest diameter, 32; height, 19.5; ap- 

 erture height, 14; breadth, 14 mm. Holo- 

 type." 



Type locality: Lower 10 feet of pink loess 

 above quarry, Plant no. 2, Mississippi Lime 

 and Materials Co., Alton, Madison County, 

 Illinois. 



Collector: M. M. Leighton, April 1920. 



Age designation: Pleistocene, Sangamon in- 

 terval. 



Remarks: Paratypes (no. P740B) and a 

 few other lots are in the ISGS collection; 

 this large variation of T. multilineata does 

 not occur commonly in the Pleistocene of 

 Illinois. 



POLYGYRA MULTILINEATA WANLESSI Baker, 



1928 

 Triodopsis multilineata wanlessi (Baker) 



Plate 4, figures 17-19 



Holotype: Cat. no. P2358, ISGS. 



Original description: Nautilus, v. 41, p. 

 132, April 1928. 



"Shell differing from recent multilineata 

 in being smaller, the body whorl somewhat 

 gibbous, of greater diameter as compared 

 with height, the aperture somewhat nar- 

 rower, and the base flattened and indented 

 about the umbilical region, which may be 

 narrowly perforate or completely closed. It 

 may be distinguished from variety algon- 

 quinensis Nason, by its usually larger size, 

 more gibbous whorls, especially the body 

 whorl, and the deeper indentation of the um- 

 bilical region. There are faint indications of 



color lines or stripes on a few specimens, but 

 the majority were probably unicolored as 

 are some specimens of multilineata at the 

 present time. Adults are usually imperforate, 

 but immature shells appear to be always 

 umbilicated. 



"Height, 13.5; diameter, 21.5 mm. Holo- 

 type." 



Type locality: About four miles west of 

 bridge at Havana, in Fulton County, Illinois. 



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



Age designation: Pleistocene, Yarmouth 

 loess. 



Remarks: Three paratypes, bearing the 

 same number as the type, and from the type 

 locality, are in the ISGS collection; other 

 paratypes, no. 144921, ANSP. 



POLYGYRA PROFUNDA PLEISTOCENICA Baker, 



1920 

 Allogona profunda pleistocenica (Baker) 



Plate 4, figures 11-13 



Holotype: Cat. no. P751, ISGS. 



Original description: Nautilus, v. 34, p. 

 66, October 1920. 



"Shell uniformly smaller than typical pro- 

 funda, more solid, with slightly higher spire 

 and proportionally smaller aperture and um- 

 bilicus; the color bands are developed in but 

 two specimens of the 19 specimens exam- 

 ined, the majority of the individuals being 

 unicolored. 



"Greatest diameter, 22; height, 14.7 mm. 

 Holotype." 



Type locality: Pink loess, near corner 

 East Sixth and Market Streets, Alton, Madi- 

 son County, Illinois. 



Collector: M. M. Leighton, April 1920. 



Age designation: Pleistocene, Sangamon 

 loess. 



Remarks: The ISGS collection contains 

 two paratypical examples, no. P751B, and 

 many other lots from deposits designated 

 Yarmouth to Early Wisconsin, referred by 

 Baker to this subspecies. 



Pomatiopsis scalaris Baker, 1927 

 Plate 1, figure 7 

 Holotype: Cat. no. P2321, ISGS. 



