Comprehensive DescriptionRead full entry
A small, dull-colored frog, adult males are 17-25 mm long and adult females, 17-35 mm. Brown to gray tan dorsal ground color with usually one or two darker chevrons. Often a narrow middorsal pinstripe or a broad pair of dorsal stripes. Marbled, stippled, or blotched on a dark brown to gray tan ground posterior thigh surface and creamy undersurface. Iris gold above and brownish below (Savage 2002).
Smooth to slightly tuberculate dorsum; head a little broader than long; snout truncate from above; large eyes with eyelids that have many low, rounded tubercles. Distinct tympanum; oblique vomerine odontophores. Distinct, small, rounded finger and toe disks; lacks digital webbing. Many small plantar tubercles; elongate inner metatarsal tubercle larger than conical outer metatarsal tubercle; lacks tarsal fold. Adult males have paired vocal slits and a distensible internal subgular vocal sac strongly granular when uninflated; lacks nuptial thumb pads (Savage 2002).
Similar Species: E. ridens has enlarged, pointed supraocular tubercles on upper eyelids, red thighs, calves, and feet. E. cruentus has large truncate and emarginate disks on fingers (Savage 2002).
Thomas Barbour in 1914 named the species after Robert S. Johnstone, Chief Justice of Grenada. Often confused with E. martinicensis (Kaiser 1997).
A Spanish-language species account can be found at the website of Instituto Nacional de Biodiversidad (INBio).