CHECKLIST OF REPTILES OF MEXICO 175 



Genotype. — SejJS murinus Lauren ti. 



Range. — North America south from Oregon, Wisconsin, and Mary- 

 land through Central America to southern Brazil and Bolivia. 



Species. — About 18, and a total of about 47 species and subspecies; 

 15 species and 41 forms, as here recognized, occur in Mexico. These 

 18 species represent 5 distinct groups, all but one of which (the 

 lemniscatus group, restricted to Central and South America, of 3 

 species and 5 forms as recognized by Burt, op. cit.), occur in Mexico. 



KEY TO MEXICAN SPECIES OF CNEMIDOPHORUS 



1. Only one frontoparietal scale " 2 



Two frontoparietals 9 



2. Dorsal surface unicolor, not striped or reticulated. hyperythrus pictus (p. 186) 

 Dorsal surface striped or reticulated, not unicolor 3 



3. Lateral stripes more or less broken; at least a few spots or cross bars present; 



body often tessellated; adults large ceralbensis (p. 188) 



Lateral stripes distinct and in even, continuous lines; spots and cross bars 

 absent; size always small 4 



4. Usually 2 or 3 longitudinal light lines in vertebral area 5 



Usually 1 median dorsal light line, forked anteriorly or not 6 



5. Usually 3 light lines along middle of back; second supraocular usually without 



granules between it and frontal hyperythrus hyperythrus (p. 187) 



Usually 2 light lines; second supraocular usually at least in part separated 

 from frontal by granules hyperythrus beldingi (p. 18G) 



6. Dorsal stripe not of same intensity and width as lateral stripes but fainter and 



usually narrower 7 



Dorsal stripe of same intensity and width as lateral stripes 8 



7. More than half of second supraocular usually in contact with frontal. 



hyperythrus schmidti (p. 187) 

 Half or less than half of second supraocular usually in contact with frontal. 



hyperythrus beldingi (p. 186) 



8. Ground color of sides (between the 2 distinct lateral stripes) reddish gray; 



dorsal ground color gray or black, abruptly contrasted with lateral ground 



color hyperythrus danheimae (p. 186) 



Ground color of sides not usually reddish gray, but often reddish or brownish; 

 dorsal ground color of same general shade as that of the sides and not in 

 sharp contrast to it h3^erythrus caeruleus (p. 186) 



9. Supraoculars normally 3; striped at least in the young 10 



Supraoculars normally 4, or, if 3, no stripes at any stage, but a pattern of small, 



scattered light spots on a dark background 15 



10. Scales between midventral scutes and anus 4 to 8; snout- vent measurement 



never exceeding 92 mm 12 



Scales between midventral scutes and anus 9 to 15; snout-vent measurement 

 reaching 138 mm 11 



11. Adults and subadults spotted, the spots often dim.guttatus guttatus (p. 179) 

 Adults and subadults (as well as young) striped, the stripes sometimes broken 



up into spots guttatus immutabilis (p. 180) 



" The species possessing this character were formerly regarded as members of the genus Vertkaria Cope. 

 Burt (U. S. Nat. Mus. Bull. 154, 1931, p. 14) has concluded, however, that the group is not a natural one, 

 since one species (ceralbensis) is related to the tesselatus group, while the others are related to the sezlineatus 

 group. The character is, furthermors, subject to a slight variation. 



