Status of Apostolepis borellii Peracca 1904 (Serpentes, Xenodontinae), with restriction of the A. nigroterminata concept

Apostolepis borellii has been considered a junior synonym of A. nigroterminata . However, examination of the holotypes showed significant differences between the species, such as head narrow (vs. wide, stocky), slandering snout (vs. wide and rounded), background color brown (vs. red), black nuchal collar wide, reaching the gular region (vs. short, not reaching gular region), tail extremity slandering with conic tip (vs. stocky, rounded tip), tail blotch complete reaching dorsals and subcaudals (vs. only dorsal, with white ring anteriorly). Apostolepis borellii occurs in the Cerrado, while A. nigroterminata , in the Amazonian Forest, two diverse biomes. The former may constitute a new group of small sized species, own from central-western Brazil to Bolivia; the latter is allocated in the nigrolineata group, both presented herein. Keywords: Brazil, Peru, Cerrado, Amazonian Forest, revalidation.