110 BULLETIN 19 9, UNITED STATES NATIONAL MUSEUM 



SPINOSUS GROUP 



Species. — Nine, with a total of 21 forms. 



Range. — Guatemala northward to southern Nevada, southwestern 

 Colorado, southern Oklahoma, and central Texas. 



KEY TO THE SPINOSUS GROUP OF SCELOPORUS 



1. Femoral pores on both thighs total 7 or more 3 



Femoral pores on both thighs total 6 or less 2 



2. Ventral surfaces immaculate in adults of both sexes. 



liorridus albiventris (p. 116) 



Sides of belly blue, frequently dark-bordered, in males; gular region barred 



in males, sometimes in females horridus oligoporus (p. 116) 



3. Supraoculars completely in contact with superciliaries, or with one to four 



very small scales between; posterior superciliary greatly enlarged; venter 



immaculate in both sexes edwardtaylori (p. 112) 



Supraoculars separated from superciliaries by at least one row of small scales; 

 posterior superciliary not enlarged; venter with distinct markings in 

 males 4 



4. Femoral pores on both thighs total 12 or less; 4 supraoculars, the fourth in 



contact with median head scales horridus horridus (p. 116) 



Femoral pores on both thighs total 13 or more; or, if 12, all supraoculars 



separated from median head scales 5 



6. Femoral pores (one side) 17 or more 6 



Femoral pores (one side) 16 or less 10 



6. A black shoulder patch present, with a hght posterior border 10 



No black shoulder patch; or, if present, without a light posterior border. . 7 



7. Snout black; a broad, black bar across head at middle of supraocular region; 



chest and middle of belly orange in males; gular region in females white, 

 with irregular, black marks; first canthal not in contact with lorilabials; 



ventral scales 44-54 8 



Snout not black, similar in color to rest of head; no black bar across head; 

 chest and middle of belly not orange; gular region in both sexes bluish, with 

 light lines following scale rows at anterior part of throat; first canthal in 

 contact with lorilabials; ventral scales 38-42..inagister lineatulus (p. 115) 



8. Femoral pores usually (84 percent) 20 or less on each side; total pore counts 



usually (80 percent) 40 or less 9 



Femoral pores usually (78 percent) 21 or more on each side; total pore counts 

 usually (83 percent) 41 or more; lateral belly patches usually not confluent 

 medially in males melanorhinus melanorhinus (p. 112) 



9. Lateral nuchal pocket greatly reduced, with very few if any granules, and very 



little if any bare skin, shallow melanorhinus stuarti (p. 113) 



Lateral nuchal pocket with numerous granules, considerable bare skin, and 

 considerable depth melanorhinus calligaster (p. 113) 



10. One or more supraoculars in contact with median head scales 14 



None of supraoculars in contact with median head scales 11 



11. Gular region barred 12 



Gular region not barred 13 



12. Dorsal scales usually more than 30; femoral pores usually more than 9 (one 



side); supraoculars usually 5 to 7 spinosus caeruleopunctatus (p. 116) 



Dorsal scales usually 30 or less; femoral pores usually 9 or less (one side); 

 supraoculars usually 4 spinosus spinosus (p. 116) 



