Sinistral specimen is on the left

Sinistral specimen: Houston, Harris Co., Texas. A. L. Mehring! 13 December, 1960. Alan Gettleman Collection. Diameter 18.4 mm.

Dextral specimen: Near San Marcos River, Palmetto State Park, Gonzales Co., Texas. W. H. McCullagh, Jr! 20 April, 2007. H. G. Lee Collection.