Key to species of Laurentomantis ( see also table II )
(1a) Larger species; male SVL 26-28 mm, female SVL up to 35 mm. Hindlimb mostly short; when adpressed along body, tibiotarsal articulation reaches at most nostril. Pulse repetition rate in notes of advertisement calls low (13/s), note duration long (1.2-2.5 s). ………. .Mantidactylus (Laurentomantis) horridus
(1b) Smaller species; male SVL up to 25 mm, female SVL up to 29 mm. Hindlimb mostly long; when adpressed along body, tibio tarsal articulation reaches at least nostril, often snout tip or beyond. Pulse repetition rate in notes of advertisement calls higher (18-40/s), note duration mostly shorter (0.4-1.5 s). ………. 2
(2a) Color in life reddish brown dorsally, dark with blue marbling ventrally. Notes of advertisement calls short (0.4-0.5 s). ………. Mantidactylus (Laurentomantis) ventrimaculatus
(2b) Color in life without reddish brown tone dorsally, and without blue marbling ventrally. Notes of advertisement calls generally long (0.4-2.5 s). ………. 3
(3a) Ventral surface of hindlimbs in life with bright red color. No vertebral stripe. Ventrally with irregular dark/light marbling. Ventral skin slightly granular, granules marked with small white spots. Head generally about as wide as long. ………. Mantidactylus (Laurentomantis) malagasius
(3b) Ventral surface of hindlimbs without red color. Posterior back with beige-orange vertebral stripe. Ventrally uniformly dark grey, sometimes with few light markings. Ventral skin smooth. Head generally slightly longer than wide. ………. Mantidactylus (Laurentomantis) striatus sp. n.