Redescription and validation of Bothriechis supraciliaris (Serpentes : Viperidae)

The populations of pitvipers from south western Costa Rica, have traditiona lly been identified as Bothriechis schlegelii (Berthold). However, in 1954 E. H. Taylor described one specimen from the area as a new subspecies, B. s chlegelii supraciliaris. Werman returned supraciliaris to synonymy with sch legelii four decades later. However, morphometry and color pattern in a SW Costa Rica population (25 specimens) differ from those of specimens (N=57) from other parts of Costa Rica and from descriptions of South American spec imens. Here the epithet Bothriechis schlegelii supraciliaris Taylor 1954, i s reestablished as a valid taxon and elevated to specific rank as B. suprac iliaris stat.nov. It is closely related to B. schlegelii from which it diff ers by its color patterns based on a uniform ground color with polymorphic dorsal designs, and its lower counts of ventral and caudal scales.