Morphology and geographical distribution of the poorly known snake Umbrivaga pygmaea (Serpentes: Dipsadidae) in Brazil

Abstract

The article describes morphology and geographical distribution of the poorly known snake Umbrivaga pygmaea in Brazil. The South American snake genus Umbrivaga Roze, 1964, is found in Colombia, Peru, Ecuador, French Guiana, Venezuela, and Brazil. The hemipenes are slightly bilobed, bearing several spines and apical discs in the distal region of the lobes, which are neither capitate nor calyculate. Inverted, the organ extended to the level of the eighth subcaudal scale. The dorsal color pattern of preserved specimens is coffee-brown; the flanks are lighter. The dorsal scales on the anterior part of the body have white edges; this part of the dorsum bears transverse dark bands that are most evident in defensive hood-displays. Although the species has a relatively wide geographic distribution, there are many gaps its range. This probably reflects a sampling bias of this relatively small, secretive snake.