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	3
2	Fewer than 25 dorsal scales in a transverse row at midbody; no distinct light stripe from mouth commissure to shoulder	Alopoglossus festae
–	More than 29 dorsal scales in a transverse row at midbody; distinct light stripe from mouth commissure to shoulder	Alopoglossus viridiceps
3	Dorsal scales hexagonal with parallel lateral edges, in transverse rows only; transverse ventral count 10	Alopoglossus lehmanni
–	Dorsal scales rhomboidal or lanceolate, in oblique and transverse rows; transverse ventral count 4–8	4
4	Keels on posterior part of dorsum form longitudinal ridges; scales on side of neck large and conical with apparent bare skin between conical scales; longitudinal dorsal count 23–24	Alopoglossus 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; longitudinal dorsal count 24–34	5
5	Scales on side of neck leaf-like (similar in shape to dorsal scales, nongranular) and somewhat imbricate; longitudinal dorsal count 24–28	Alopoglossus angulatus
–	Scales on side of neck small and granular; longitudinal dorsal count 29–34	6
6	Ventral scales smooth	Alopoglossus buckleyi
–	Ventral scales distinctly keeled	Alopoglossus atriventris