Pleistocene Snails from San Patricio County, Texas 45 



Praticolella berlandieriana ( Moricand ) 

 PI. 2, figs. 4a-c. 



Description. Shell finely, but unevenly striate; otherwise present specimens are 

 in essential agreement with those of Pilsbry (1940, p. 694). Shells are white with 

 no color pattern preserved. 



Measurements. Measurements for Praticolella berlandieriana are given in 

 Table 14. 



Distribution. Praticolella berlandieriana is a southern species occurring in 

 Arkansas, and central and southern Texas; in Mexico, Tamaulipas and Nuevo Leon 

 (Pilsbry 1940, p. 694). 



Ecology. This is a southern species occurring in moderately dry to semiarid 

 country. 



Remarks. The first record of Praticolella berlandieriana as a fossil is that of 

 Conkin and Conkin (1961, p. 12) in which it was reported as a fragment ques- 

 tionably referred to P. berlandieriana from the upper 30 feet of the loess at Vicks- 

 burg, Mississippi. The species has been reported also from the Wisconsinan of 

 Bee County, Texas (Conkin and Conkin, 1962, p. 348). 



Table 14. Measurements of Praticolella berlandieriana in mm. 



Section 

 and bed 

 Specimen nos. Length 



18 2,6 8.2 



19, PI. 2, figs. 4a-c 2, 6 8.8 



20 2,6 8.5 



Pupilla blandi Morse 

 PI. 1, figs. 8a, 8b. 



Description. Present specimens are in essential agreement with those forms 

 described by Pilsbry (1948, p. 931). Shell is white with original color pattern 

 not preserved. 



Measurements. Measurements for Pupilla blandi are given in Table 15. 



Distribution. Pilsbry ( 1948, p. 931 ) gave the distribution of Pupilla blandi 

 as follows: "Rocky Mountain region, from Montana and Red Deer, Alberta, to 

 New Mexico; west to Nevada; eastward in the semiarid region (mainly as a fossil 

 or in river drift) to McLean Co., North Dakota (at Ft. Berthold, type loc. ); Brule 

 Co., South Dakota; Phillips Co., Kansas; Comal Co., Texas." 



Ecology. Leonard (1950), p. 28) discussed the ecology of Pupilla blandi: 

 "It has disappeared from the Great Plains province, and occurs in regions of higher 

 humidity and lower mean temperature. In the southern part of its range [see 

 paragraph above on distribution] it fives at altitudes up to 10,000 feet, especially 

 in aspen groves." 



Remarks. Except for Pilsbry 's (1948, p. 933) reference to Pupilla blandi 

 either as a fossil washed from Pleistocene deposits on the river banks, or in river 

 drift in Comal County, Texas, the species is not previously known from the geo- 

 logic column of Texas, and does not occur in Texas today. This species is good 

 evidence for a cool and humid climate during the deposition of the Wisconsinan 

 deposits of the Fordyce Quarry, and the subsequent trend to warmth and aridity 

 on the Gulf Coast of Texas since the Wisconsinan, 



Max. 

 diam. 



Min. 

 diam. 



Apert. 

 height 



Apert. 

 width 



No. of 

 whorls 



10.0 



8.5 



5.5 



4.1 



&A 



10.5 



8.9 



6.2 



4.5 



5i/ 4 



10.0 



8.1 



5.5 



3.9 



m 



