CHECKLIST OF REPTILES OF MEXICO 29 



Genera. — About 25, of which 6 occur in Mexico. 

 Range. — World-wide except Aiistraha and East Indies. 



KEY TO MEXICAN GENERA OF EMYIDAE 



1. Plastron hinged, movable; no inframarginals Terrapene (p. 34) 



Plastron fixed, immovable; inframarginals present 2 



2. Alveolar surface of upper jaw with a ridge either smooth or toothed, parallel to 



labial cutting edge 5 



Alveolar surface of upper jaw ridgeless, smooth 3 



3. A strong interrupted median keel on carapace, with a marked tubercle at the 



end of each vertebral; a low dorsal crest of enlarged compressed scales on 

 tail; bridge much shorter than posterior lobe of plastron. 



Malaclemys (p. 36) 



Dorsal keel on carapace absent or continuous, not tuberculate; no crest 



of scales on tail 4 



4. Bridge much shorter than posterior lobe of plastron Clemmys (p. 37) 



Bridge longer than posterior lobe of plastron Geoemyda (p. 29) 



5. Rear of carapace perfectly smoothly rounded, edges of all plates even, no 



notches except a median rear one; a terminal notch flanked on either side by 

 a projection on upper jaw, and cutting edge of lower jaw smooth. 



Chrysemys (p. 33) 



Rear of carapace at least somewhat serrate; no terminal notch flanked on 



either side by a projection in upper jaw, or if so cutting edge of lower jaw 



serrate Pseudemys (p. 31 ) 



Genus GEOEMYDA Gray 



Geoemyda Gray, Proc. Zool, Soc. London, 1834, p. 100.— Wettstein, Sitzb. Akad. 



Wiss. Wien, math.-naturw. Kl., Abth, 1, vol. 143, 1934, pp. 17-19 (key to 



American species). 

 Rhinoclemys Gray, Ann. Mag. Nat. Hist., ser. 3, vol. 12, 1863, p. 182 (genotype, 



Geoclemmys annulata Gray). 



Genotype. — Testudo spengleri Gmehn. 



Range. — India to Japan and the Malay Archipelago; the coasts 

 of central Mexico south into South America. 



Species. — Nineteen species and subspecies are known, nine in the 

 Americas, four in Mexico. 



KEY TO MEXICAN SPECIES OF GEOEMYDA 



1. Bridge yellow areolata (p. 30) 



Bridge black, uniform or with a few yellow markings 2 



2. Upper jaw hooked or smooth; plastron dark with a yellow margin.rubida (p. 30) 

 Upper jaw notched; plastron yellow, with a broad dark median stripe 3 



3. Carapace almost uniform brown, without distinct markings, its entire border 



strongly bowed, nowhere straight; sides of head in front of eye with usually 



2, sometimes 3, bright horizontal lines pulcherrima incisa (p. 30) 



Carapace olive-brown, with bright, yellow-red concentric or hieroglyphic 

 pattern of lines on each scale; young with dark, light-centered spots on 

 costals; only lateral border of carapace strongly bowed; sides of head in 

 front of eye always with 3 lines pulcherrima pulcherrima (p. 30) 



