160 BULLETIN 187, UNITED STATES NATIONAL MUSEUM 



19. The spots in the two rows on each side, between the vertebral and lat- 



eral stripes, fused together over most of body (not just on neclj) 21 



The spots in the two rows on each side, between the vertebral and lateral 

 stripes, not fused together except on neck; spots disappearing poste- 

 riorly or not 20 



20. Scale rows anteriorly 17 : 21 



Scale rows anteriorly 19 23 



21. Dark color of dorsal surface of head and nape with a clearly defined 



dark-edged indentation a little posterior to angle of mouth, extending 

 anterodorsally toward midoccipital region; scale rows usually 19 on 



some part of body ; spots usually distinct on most of body 22 



Dark color of dorsal surface of head and nape lacking any clearly defined, 

 dark-edged light indentation behind angle of mouth; scale rows sel- 

 dom over 17 on any part of body ; no spots distinct on body posterior 

 to nape, dorsum nearly uniform brown scalaris godmani 



22. Scale rows posteriorly usually 17 (94 percent) ; anterior scale rows 



usually 19 (88 percent) scalaris scaliger 



Posterior scale rows usually less than 17 (70 percent) ; anterior scale 

 rows usually less than 19 (93 percent) scalaris scalaris 



23. Spots in upper row of the two series between vertebral and lateral light 



lines fused together and usually with the spots in the outer row, the 

 latter spots remaining distinct from each other; ground color red 

 between spots of outer row (above lateral stripe) ; middorsal stripe 



well-defined sirtalis parietalis 



Spots not fused in such a manner, although sometimes poorly defined 

 or corresponding spots of the two rows fused together; ground color 

 not red ; middorsal stripe distinct or not 24 



24. Middorsal stripe with continuous, straight edges, covering one and two 



half scale rows ; rounded dark spots on anterior edges of ventrals on 

 sides of at least part of belly ; ventrals seldom over 157, caudals sel- 

 dom over 76 25 



Middorsal stripe usually covering only the vertebral row, or indistinct, or 

 absent ; if broader, not straight edged and ventrals and caudals more 

 numerous ; belly not spotted 26 



25. Supralabials strongly barred ; head dark above, the color fused with that 



of nape ; ventrals 136 to 140 sumichrasti praeocularis 



Supralabials not or weakly barred ; head light above, its color sharply 

 differentiated from that of nape ; ventrals 144 to 167. 



sumichrasti cerebrosus 



26. No median light stripe on any part of body, its place occupied by a 



median series of dark spots 31 



A median light stripe at least anteriorly ; no median series of dark spots — 27 



27. A very distinct median light stripe throughout length of body ; and dark 



spots present on the scales below the lateral light line at least ante- 

 riorly, visible without spreading the scales; ventrals seldom less than 



149 28 



Median light stripe indistinct or absent posteriorly ; or, if distinct poste- 

 riorly, no dark spots on the scales below the lateral light line 29 



28. Ventrals 167 or more in males, 163 or more in females eques cyrtopsis 



Ventrals 166 or less in males, 162 or less in females eques eques 



29. Ventrals 155 to 166 ordinoides errans 



Ventrals fewer, 136 to 153 30 



