CHECKLIST OF REPTILES OF MEXICO 41 



only recently been reported in Mexico, and may possibly have been 

 transported by man from Central America. 



It would appear from collections that all these genera have very 

 limited or discontinuous distribution in Mexico. 



The genera Phyllodactylus, Sphaerodactylus, and Thecadactylus very 

 probably reached Mexico without the aid of man. 



KEY TO MEXICAN GENERA OF GEKKONIDAE 



1. Eyelid fully developed, body covered with small cycloid somewhat imbricating 



scales, with or without somewhat larger tubercles on body or tail; a few 

 preanal pores present; digits cylindrical, never distinctly widened. 



Coleonyx (p. 41) 

 Eyelid rudimentary, not capable of covering eye 2 



2. Under surface of digits unwidened, covered with flat smooth scales, lacking 



leaflike lamellae; no preanal or femoral pores; diminutive size. 



Gonatodes (p. 45) 



A part of under surface of digits with widened lamellae present; femoral pores 



present or absent; size variable 3 



3. A single widened terminal lamella on digits with the claw lateral to it; no 



femoral pores; diminutive in size Sphaerodactylus (p. 52) 



Digits with one pair or several pairs of widened lamellae 4 



4. A single terminal pair of lamellae, the claw between them; size larger; preanal 



and femoral pores absent in Mexican forms Phyllodactylus (p. 46) 



Part of under surface of digits widened with a single or double series of lamellae, 

 usually not present under terminal joint; pores present or absent 5 



5. Subdigital lamellae undivided, in a single row Aristelliger (p. 51) 



Subdigital lamellae in two rows, divided medially 6 



6. Tail with enlarged, sometimes spiny tubercles, forming longitudinal rows or 



transverse whorls; body with at least some enlarged tubercles, which may be 



flat or trihedral; femoral or preanal pores present Hemidactylus (p. 49) 



Tail and body lacking spines or enlarged tubercles; pores present or absent. _ 7 



7. Tail with flat ventral surface, serrated lateral edge, and a median row of en- 



larged scales on ventral surface; a long, doubly curved series of femoral 



pores; a fold of skin on posterior side of thigh and leg Peropus (p. 51) 



Tail rounded, tapering, covered with imbricate scales, a little larger on under 

 surface; no femoral or preanal pores; no skin fold on hind leg. 



Thecadactylus (p. 49) 



Genus COLEONYX Gray 



Coleonyx Gray, Ann. Mag. Nat. Hist., vol. 16, 1845, p. 162. — Klauber, Trans. 



San Diego Soc. Nat. Hist., vol, 10, No. 11, 1945, pp. 133-216. 

 Brachydachjliis Peters, Monatsb. Akad. Wiss. Berlin, 1863, p. 41 (type, B. 



mitratus Peters). 



Genotype. — Coleonyx elegans Gray. 



Range. — The genus extends from Southwestern United States to 

 Panama. 



Species. — Five, with a total of 12 forms. Four species and 10 

 forms are known or are to be expected in Mexico. 



