CHECKLIST OF REPTILES OF MEXICO 123 



Tail without distinct alternating dark and light bands of nearly equal width; 

 bands about tail not complete toward tip; dorsal scales 40 or less 14 



14. Dorsal scales 31 or less 15 



Dorsal scales 32 or more 16 



15. A middorsal series of very large, dark blotches, sometimes fused bandlike; 



all except males with a pair of parallel, closely placed dark lines down 

 middle of throat; collar 4 scales long or less. 



mucronatus mucronatus (p. 124) 



No middorsal series of dark blotches; parallel throat lines absent; collar 



involving 4)4 scale lengths or more mucronatus omilteraanus (p. 124) 



16. Each dorsal scale row, in adult males, with a longitudinal light Hne; dorsals 



30 to 38 mucronatus aureolus (p. 124) 



Scale rows not with continuous lines 17 



17. Nuchal black collar 4 or 5 scales wide, bordered anteriorly and posteriorly 



by a light band 1 or 1J4 scales wide; each border interrupted medially by a 

 light scale; snout-vent length often more than 100 mm., reaching 143 



mm cyanogenys (p. 125) 



Not so; maximum snout-vent length 100 mm 18 



18. Lateral body scales distinctly decreasing in size laterally, at a point halfway 



between axilla and groin, distinctly smaller than dorsal scales 19 



Lateral body scales not decreasing in size laterally at least up to a point half- 

 way between axilla and groin, where they are still subequal to, or even a 

 little larger than, middorsal scales 20 



19. Dorsal scales on lower foreleg about half size of those on upper foreleg; dark 



transverse streaks in lateral belly patches; nuchal collar covering six scales 



medially, or more jarrovii sugillatus (p. 128) 



Dorsal scales on lower foreleg but little if any smaller than those on upper 

 foreleg; no dark streaks in lateral beUy patches; nuchal collar less than four 

 scales long middorsally jarrovii immucronatus (p. 128) 



20. Supraoculars essentially in 1 row; if an outer row is evident, it is composed of 



scales much smaller than those of inner row, and usually number no more 



than two jarrovii jarrovii (p. 128) 



Supraoculars in 2 rows, those of outer row a little smaller than those of inner, 

 usually numbering 3 or more 21 



21. Adult males black above and below, with orange areas and spots on sides of 



head, belly, and tail; only throat, underside of tail, and posterior surface of 

 hind leg not black; females somewhat similar, very dark above, the collar 

 poorly defined, young with poorly defined, narrow, light borders on neck 



collar; dorsal scales average 37.5 jarrovii oberon (p. 129) 



Adult males light brown above, with very broad, very well defined nuchal 

 collar; a median area on belly white except in very largest males; sides of 

 abdomen blue, black-edged; females and young with more distinct light 

 borders on nuchal collar; dorsal scales average 40.6. jarrovii minor (p. 128) 



SCELOPORUS SERRIFER SERRIFER Cope 



Sceloporus serrifer Cope, Proc. Acad. Nat. Sci. Philadelphia, 1866, p. 124. — 

 Smith, Univ. Kansas Sci. Bull., vol. 24, 1936 (1938), pp. 558-564, figs. 5, 6, 

 pi. 47, fig. 2. 



Sceloporus serrifer serrifer, Smith, Publ. Field Mus. Nat. Hist., zool. ser., vol. 26, 

 1939, p. 212, fig. 23. 

 861316—50 9 



