Abstract
An examination of types representing Guatemalan species of Tantilla of the T. taeniata group reveals that current concepts for several species are incorrect and that several species remain undescribed. Tantilla taeniata Bocourt (1883) is a valid species occurring in the seasonally dry highlands of south-central and southeastern Guatemala; it is characterized by a broad pale middorsal stripe involving the vertebral scale row and adjacent portions of the paravertebral rows, a ventrolateral coloration that is not darker than the pigment of the dorsolateral stripe, and relatively few ventrals. This species does not occur o the mesic Atlantic versant of Guatemala as previously thought; the large species inhabiting the Atlantic versant is described as new. The name Tantilla jani may be associated with a small, but robust, species inhabiting the Pacific versant and characterized by an incomplete nuchal collar. Most individuals previously ascribed to T. jani are a gracile species having a complete collar; these represent an undescribed species.