Type: Destroyed, formerly at MSNG according to golay et al., 1993, Endogly. Venom. Snakes World 478pp..
Two subspecies, namely M. h. hemprichii (Jan, 1858) and M. h. ortoni Schmidt, 1953, were recognized by Roze, 1983.
The Amazonian slopes of the Andes in Colombia, Ecuador, Peru, and Bolivia, eastward across the upper portion of the Amazon Basin to the Guiana highlands and the upper Orinoco region from eastern Colombia through southern Venezuela eastward including Guyana, Suriname, and French Guiana, as well as most of Brazil north of the Amazon in the states of Amazonas, Roraima, Rondonia, and Amapá. It occurs on both sides of the Amazon in Pará (Brazil).
Distribution: Colombia, Venezuela (TF Amazonas), Guyana, French Guiana, Surinam, Ecuador, Peru, Brazil (Para, Rondonia), Bolivia hemprichii: E Colombia, S Venezuela, the Guianas, NE Brazil;
Type locality: Colombia. ortoni: Upper Amazon of Colombia, Ecuador, Peru, Bolivia;
Type locality: Pebs (Pebas fide SCHMIDT 1955), Peru. Holotype: MCZ 12423, male.
Catalog Number: USNM 304362
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Year Collected: 1988
Locality: Porto Velho, 52 km E of, Hydroelectric Power Plant of Samuel, Rondônia, Brazil, South America
Elevation (m): 85 to 85
- Paratype: Roze, J. A. & da Silva, N. J. 1990. Bulletin of the Maryland Herpetological Society. 26 (4): 170, figure 1.