40 James E. Conkin, Barbara M. Conkin, William T. Mason, ]r. 



Table 4. Measurements of Euconulus chersinus trochulus in mm. 



Specimen 



Section 



and bed 



nos. 



Length 



Max. 

 diam. 



Min. 

 diam. 



Apert. 

 height 



Apert. 

 width 



No. of 



whorls 



73 



74, PI. 2, figs. 5a-c ... 



2,5 

 ... 2, 5 



2.7 

 2,3 



3.2 

 2.9 



2.7 

 2.6 



0.9 



0.6 



1.7 

 1.3 



6V4 





Gastrocopta 

 PI. 1, 



armifera 

 figs. 12a- 



(Say) 









Description. Franzen and Leonard (1947, p. 329) gave the range in meas- 

 urements of their specimens as follows: height, 3.6-5.0 mm; diameter, 2.1-2.5 mm; 

 apertural height, 1.4-1.8 mm; apertural width, 1.35-1.45 mm; number of whorls, 

 5i/2 to 7; however, present specimens are longer, narrower, with more whorls, and 

 the apertures are smaller. Shells are weathered and white; there are six denticles. 



Measurements. Measurements for Gastrocopta armifera are given in Table 5. 



Distribution. "It [Gastrocopta armifera] inhabits almost the whole country 

 east of the continental divide, but is lacking in southwestern New Mexico, south- 

 ern Texas, southern Florida, and the higher parts of the Alleghany mountain sys- 

 tem. It prefers limestone districts" (Pilsbry, 1948, p. 875). 



Strecker (1935, p. 19) reported Gastrocopta armifera in Texas north and 

 west of the Gulf Coastal Plain. 



Ecology. "Gastrocopta armifera. is a gregarious species occurring commonly 

 on wooded slopes, near or removed from a stream. It is to be found under dead 

 wood, limestone rocks, or light cover or leaf mold or other debris. G. armifera 

 frequently occurs under boards or rocks in gardens" (Franzen and Leonard, 1947, 

 p. 329). 



Table 5. Measurements of Gastrocopta armifera in mm. 



Specimen 



37 



38 



39, PI. 1, figs. 12a-c 



40 



41 



42 



Section 



and bed 



nos. 



Length 



Diam. 



Apert. 

 height 



Apert. 

 width 



No. of 



whorls 



2,5 



5.0 



2.0 



1.3 



1.1 



71/4 



2,5 



4.9 



2.0 



1.2 



1.0 



7 



2,5 



5.0 



2.0 



1.3 



1.2 



7 



2,5 



5.0 



1.9 



1,3 



1.1 



7 



2,5 



4.9 



2.0 



1.1 



0.9 



m 



2,5 



5.0 



2.0 



1,3 



1.1 



7 



"Gastrocopta armifera is distributed in North America in regions of diverse 

 climates .... [and] is tolerant of, and adaptable to various climatic conditions. 

 In the prolonged dry, hot summer months, G. armifera is able to aestivate, making 

 possible its survival in Kansas, especially in the western part of the state, where 

 the summer droughts are often severe" (Franzen and Leonard, 1947, p. 330). 



Remarks. Gastrocopta armifera has previously been reported as a fossil from 

 Texas only in the Yarmouthian from Roberts and Hartley counties in the Pan- 

 handle (Leonard, 1950, p. 29). The species is herein reported from the Gulf 

 Coast of Texas for the first time in the fossil form; the species is apparently absent 

 from the Recent snail fauna of the Gulf Coast. 



