Scutellational, head pattern, and meristic and mensural data from 162 speci
mens of the black-headed snakes, Tantilla rubra rubra, T. r. diabola, and T
. r. cucullata were analyzed to clarify the taxonomic relationship between
specimens from Mexico and Guatemala (T. r. rubra) and those from Texas (T.
r. diabola and T. r. cucullata). The Texas population is relegated to T. cu
cullata, distinguished from T. rubra in Mexico and Guatemala in having more
ventral + subcaudal scales, reduced reddish coloration, and either a solid
black head cap or at least some evidence of middorsal division of the whit
e nuchal collar. Tantilla diabola Fouquette and Potter 1961 is confirmed as
a junior subjective synonym of the black-hooded snake T. cucullata Minton
1956. Tantilla miniata Cope 1863 and T. morgani Hartweg 1944 are relegated
to the synonymy of T. rubra. Application to the international Commission on
Zoological Nomenclature will be made to conserve T. rubra Cope 1876.