  The populations of pitvipers from south western Costa Rica, have
traditionally been identified as Bothriechis schlegelii (Berthold). However, in
1954 E. H. Taylor described one specimen from the area as a new subspecies, B.
schlegelii supraciliaris. Werman returned supraciliaris to synonymy with
schlegelii 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 specimens.
Here the epithet Bothriechis schlegelii supraciliaris Taylor 1954. is
reestablished as a valid taxon and elevated to specific rank as B.
supraciliaris stat.nov. It is closely related to B. schlegelii from which it
differs by its color patterns based on a uniform ground color with polymorphic
dorsal designs, and its lower counts of ventral and caudal scales.
