78 BULLETIN 194, UNITED STATES NATIONAL MUSEUM 



KEY TO MEXICAN SPECIES OP HYLA 



1. A dark stripe (absent in cdrdenasi) from tip of snout to eye, and from eye 



diagonal to point on side of body, and usually bordered by light color 

 or stripe above or below or both; body usually green in life with or 

 without dark spots on back; terminal toe disks small with never more 

 than a vestige of web between fingers; apparently largely terrestrial 

 (euphorbiacea, an exception, is apparently largely arboreal). 



ezimia group, _ 2 

 No dark stripe from tip of snout to eye and from eye diagonally to a 

 point low on sides of body (sometimes indicated in phaeota, a large 

 species, the body not green) 8 



2. Skin above strongly granular or pustulate; Baja California; 42 mm. 



regilla (p. 82) 

 Skin smooth or minutely corrugated 3 



3. Posterior and to a lesser extent anterior region of femur and groin with 



blackish or brownish reticulation enclosing rounded or irregular yellow- 

 cream spots; Veracruz, Puebla, and Oaxaca; 37mm_ euphorbiacea (p. 82) 

 Posterior and anterior region of thigh with equally distributed pigmenta- 

 tion without spots and reticulations 4 



4. Tibiotarsal articulation to eye or a little be.yond, but not to nostril 5 



Tibiotarsal articulation (heel) to nostril or tip of snout; head less wide; 



terrestrial forms; disks smaller 7 



5. Diameter of eye greater than length of snout; eyelid width greater than 



interorbital width; snout bluntly rounded; uniform green without 

 lateral marks on snout and behind eye; Puebla; 39 mm__ cardenasi (p. 83) 

 Diameter of eye distinctly less than length of snout 6 



6. Snout oval; a distinct light-edged dark band on head and side; eyelid less 



than interorbital width; widespread on the Mexican plateau; 35 mm. 



eximia (p. 83) 

 Snout blunt; head wider; tibiotarsal articulation to between eye and 

 nostril; head wide; eyelid 1>^ times interorbital distance; color olive- 

 gray and black, the lateral stripe dim on head and body, not light 

 edged; arboreal; digital disks rather large; Guerrero; 41 mm. 



arboricola (p. 83) 



7. Larger; green with well-defined, light-edged, dark stripe on side of head 



and body; dark spots on dorsum edged with silvery white; front side 

 of tibia blackish bordered by a white line, continued on foot; Veracruz 



to Morelos in high mountains; 50 mm lafrentzi (p. 84) 



Somewhat smaller; with less distinct stripe on body; color green (rarely 

 olive, gray, or brown); dorsal spots not edged with light color; anterior 

 edge of tibia with brown spots; posterior edge of tibia without white 

 line; Chihuahua; 42 mm wrightorum (p. 84) 



8. Entire side of head, and more or less the side of body, darker than, and 



contrasting more or less with, dorsal coloration; lighter dorsal color 

 terminating at a point near nostril (never extending to lip) ; pigment 

 forming elaborate star-shaped flecks; whitish part of dorsal coloration 

 appears under lens as extremely minute, closely approximated circles; 

 occasionally (in specimens captured at night) no very strong dififerenti- 

 ation between the dorsal and lateral coloration, but under lens, pig- 

 ment seen to be in larger flecks on sides loquax group 9 



Side of head and body not darker than dorsal coloration, usually 

 lighter, with or without light spots or dark spots or both 16 



