CHECKLIST OF REPTILES OF MEXICO 161 



Scales in 19 rows about middle of body; no stripes, but scales with black 

 dots altamirani (p. 163) 



3. Three supraoculars; no postnasal; 1 postmental 4 



Four supraoculars ; postnasals and postmentals variable 5 



4. Parietals enclose interparietal; scale rows about middle of body, 24; seventh 



labial in contact with upper secondary temporal dugesii (p. 169) 



Parietals not enclosing interparietal; scale rows usually 24; seventh labial 

 not in contact with upper secondary temporaL.lynxe furcirostris (p. 163) 



5. Postmentals normally 2 6 



Postmental normally 1 12 



6. Body without white stripes at any time; lateral scale rows generally oblique; 



young black with a blue tail; head with cream spots; adults oUve with 

 darker areas on scales; limbs large, overlapping when adpressed; scales 



26-28 rows; 125 mm. snout to vent obsoletus (p. 165) 



Body with white stripes in young, retained in adult, or'approaching uniform 

 ohve coloration in adults, especially old males; lateral scale rows parallel; 

 young never black but usually with blue or pink (red) or orange tail 7 



7. Dorsolateral light stripes distinct and confined to third scale row. 



multivirgatus (p. 165) 



Dorsolateral light stripes not involving third scale row at all, or else including 



also second scale row 8 



8. Median light Une beginning between arms running forward bifurcating on 



head; or median hne lost and the bifurcating Unes only, remain on head. 9 



No trace of a median light line or bifurcating lines on head; usually 4 light 



lines, 2 lateral and 2 dorsolateral 10 



9. Parietals enclose interparietal; scale rows usually 28 at middle of body; post- 



nasal usually present; median white Une to shoulder; limbs short, not 



touching when adpressed callicephalus (p. 164) 



Parietals not enclosing interparietal; bifurcating lines on head, but median 

 line obsolete; postnasal absent; limbs touch in young when adpressed, in 

 adults separated by 3 or 4 scale lengths; postmental single or divided; 26-28 

 scale rows; maximum size about 70 mm tetragrammus (p. 165) 



10. Parietals enclose interparietal; 24 scale rows; seventh labial broadly in contact 



with upper secondary temporal; tail orange in young; 4 light lines retained 



in adults; limbs fail to touch when adpressed lagtmensis (p. 167) 



Parietals do not enclose interparietal 11 



11. Snout-vent length greater than 75 mm., or interparietal nearly parallel- 



sided; specimens under 50 mm. snout-vent length with pink tail (no blue); 

 8 supralabials on each side (98 percent) ...gilbertirubricaudatus (p. 167) 

 Snout-vent length not more than 75 mm.; interparietal bluntly wedge-shaped; 

 juveniles, usually adults, with blue tail; 7 supralabials on one or both sides 

 (94 percent) skiltonianus (p. 167) 



12. A median light line bifurcating on frontal 13 



Median light line present or absent, if present bifurcating behind frontal. 14 



13. Median line from middle of body bordered with darker, and bifurcating on 



anterior half of frontal; limbs separated when adpressed; usually 24 scales 



about body lynxe lynxe (p. 163) 



Median light line bifurcating on the posterior part of frontal, or all lines lost 

 in adult olive coloration; limbs overlapping when adpressed; subcaudals 

 widened; maximum snout to vent length, 100 mm._.suinichrasti (p. 164) 



14. Parietals enclosing interparietal 15 



Parietals not enclosing interparietal 17 



