Notes on the Fauna of the Chipola Formation-XXXVII Variation in the Shell Morphology of Calliostoma Ceramicum (Gastropoda:Trochidae)

Abstract

Over two hundred specimens of Calliostoma were collected "in situ" from locality TU 951 along Tenmile Creek in Calhoun County, Florida. The majority were Calliostoma ceramicurn (Dall, 1892). An examination of this species reveals a high degree of variation in shell morphology. In at least one instance, the shell structure and sculpture of C. ceramicum differed so much from the holotype that this investigator was tempted to identify it as a new species. The purpose of this note is to document the degree of variability of C. ceramicum.