6.4 



9.1 



8.1 



3.1 



5.5 



6 



5.5 



8.7 



8.2 



3.1 



5.0 



ty* 



5.4 



8.8 



8.0 



2.9 



4.6 



5i/ 2 



5.5 



8.7 



8.1 



3.0 



4.6 



5V ? 



5.6 



8.3 



7.9 



3.0 



4.6 



534 



5.2 



8.7 



7.9 



3.0 



4.5 



51/9 



48 James E. Conkin, Barbara M. Conkin, William T. Mason, Jr. 



Distribution. Iowa, Kansas, Missouri, Arkansas, Oklahoma, Texas (Bowie, 

 Cooke, Dallas, and Wood counties), Mississipppi, Alabama, Tennessee, Kentucky, 

 Illinois, and Indiana. East Texas to Virginia, and Washington, D. C. (Pilsbry, 

 1940, p. 680). 



Ecology. Stenotrema leai aliciae is characteristically a snail of the humid 

 lowlands, but has been found at 4,000 feet elevation in Virginia (Pilsbry, 1940, 

 p. 680). 



This species has been reported from the late Wisconsinan Berclair terrace of 

 Bee County, Texas by Conkin and Conkin (1962, p. 348). Forsyth (1958, p. 8) 

 records Stenotrema leai aliciae from the Caryan of the Wisconsinan in Illinois. 



Table 19. Measurements of Stenotrema leai aliciae in mm. 



Section 



and bed Max. Min. Apert. Apert. No. of 



Specimen nos. Length diam. diam. height width whorls 



1, PI. 1, figs, la-c 2, 5 



2 2,5 



3 2,5 



4 2,5 



5 2,5 



6 2,5 



Strobilops texasiana (Pilsbry and Ferriss) 

 PI. 1, figs. 5a-c. 



Description. Specimens are in essential agreement with those forms described 

 by Pilsbry (1948, pp. 858-860). 



Measurements. Measurements for Strobilops texasiana are given in Table 20. 



Distribution. Strobilops texasiana is known from southwest, south, and north- 

 east Texas and Louisiana, Arkansas, and Oklahoma (Pilsbry, 1948, p. 858). 



Ecology. Leonard ( 1950, p. 34 ) commented on the ecological requirements 

 of Strobilops as follows: "The genus Strobilops comprises small snails which live 

 on decaying logs and dead leaves in moderately humid forests. It is distributed in 

 North America from the 100th meridian eastward; it ranges from Ontario, Canada, 

 on the north to Guatemala." 



Remarks. "In Europe, a number of fossil species are known from Eocene to 

 Pliocene, when the genus became extinct there. The genus is sporadically dis- 

 tributed over the world elsewhere. In North America, Strobilops appears first in 

 Aftonian faunas." (Leonard, 1950, p. 34). 



Strobilops texasiana has been reported from the drift along the Guadalupe 

 River in Comal County, Texas (Pilsbry, 1948, p. 858). Otherwise, this is appar- 

 ently the first record of the species in the Pleistocene. 



Table 20. Measurements of Strobilops texasiana in mm. 



Section 



and bed Max. Min. Apert. Apert. No. of 



Specimen nos. Length diam. diam. height width whorls 



67 2,5 



68 2,5 



69, PI. 1, figs. 5a-c .... 2, 5 



70 2,5 



2.0 



2.3 



2.1 



0.8 



1.0 



51/9 



2.1 



2.4 



2.2 



0.9 



1.1 



5i/9 



2.0 



2.8 



2.2 



0.8 



1.0 



534 



2.1 



2.5 



2.2 



0.9 



1.1 



53/4 



