Key to the species (adult specimens) of genus Bolitoglossa in Amazonian Brazil

1 Ratio distance between anterior corners eyes and head length greater than 0.5 in adult males and females................ 2

1’ Ratio distance between anterior corners eyes and head length less than 0.5 in adult males and females................................................................................................... Bolitoglossa altamazonica

2 Size moderate, standard length adult females less than 49 mm in adult males 30–54.1 mm ........................... 3

2’ Size large, standard length adult female greater than 49 mm in (data for males unavailable).... Bolitoglossa madeira sp. nov.

3 Head moderately narrowed, standard length 6.6–8.0 times head width in adult males and 6.5–8.2 times head width in adult females............................................................................................ 4

3’ Head wide, standard length 6.3– 6.9 times head width in adult males and 6.1–6.9 times head width in adult females................................................................................... Bolitoglossa caldwellae sp. nov.

4 Tail relatively long, ratio tail length to standard length 0.75–1.03 (mean 0.9) in adult males and 0.71–0.99 (mean 0.86) in adult females, original tail becoming thinner at about half its length; snout rather short, snout length ≥ 40% of head length in adult males and females; premaxillary teeth moderate in size, 1–3 in adult males and 0–4 in adult females.. Bolitoglossa paraensis

4’ Tail moderately short, ratio tail length to standard length 0.73–0.84 (mean 0.78) in adult males and 0.77–0.93 (mean 0.84) in adult females, original tail becoming thinner at about one-third of its length; snout rather long, snout length ≤ 44% of head length in adult males and females; premaxillary teeth rather small, 3–5 in adult males and 1–3 in adult females....................................................................................... Bolitoglossa tapajonica sp. nov.