Key to the species of Alopoglossus

This key is adapted from Torres-Carvajal & Lobos (2014) and does not reflect the phylogenetic relationships of the species.

1. A double longitudinal row of widened gular scales; dorsal scales lanceolate in transverse rows only.................... 2

- No double longitudinal row of widened gular scales; dorsal scales hexagonal in transverse rows only or rhomboidal in oblique and transverse rows.................................................................................. 4

2. Presence of distinct light stripe from mouth commissure to shoulder................................... A. viridiceps

- No distinct light stripe from mouth commissure to shoulder................................................... 3

3. Ventral scales keeled, pointed................................................................... A. embera

- Ventral scales smooth, rounded................................................................... A. festae

4. Dorsal scales hexagonal with parallel lateral edges, in transverse rows only; transverse ventral count 10........ A. lehmanni

- Dorsal scales rhomboidal or lanceolate, in oblique and transverse rows; transverse ventral count 4–8................... 5

5. Keels on posterior part of dorsum form longitudinal ridges; scales on side of neck large and conical with apparent bare skin

between conical scales........................................................................... A. copii - Keels on posterior part of dorsum do not form longitudinal ridges; scales on side of neck small and granular or keeled and somewhat imbricate without apparent bare skin between scales................................................ 6

6. Scales on side of neck small and granular.................................................................. 7

- Scales on side of neck similar in shape to dorsals, nongranular, keeled, imbricate.................................. 8

7. Ventral scales distinctly keeled................................................................ A. atriventris

- Ventral scales smooth......................................................................... A. buckleyi

8. Four pairs of chin shields; third pair of chin shields separated from gulars by large scales...................... A. meloi

- Three pairs of chin shields; third pair of chin shields in direct contact with gulars or separated from them by small, rounded or granular scales.............................................................................. A. angulatus