408 3. IGUANIDJE 



and terminal portion of tail keeled, those on central part of 

 belly and proximal part of ventral surface of tail smooth. 

 Tympanum not covered with scales. Long series of from 

 14 to 26 femoral pores present. Males usually with en- 

 larged postanal plates. Females much larger than males. 

 The ground color above is brownish, yellowish, reddish, 

 or grayish, usually darker laterally. A large brown patch 

 occupies each side of the neck. On the back are undulate 

 cross-bands or large irregular blotches of dark brown, 

 usually in a dorsal and a lateral series. These blotches may 

 be connected with those in front and behind and form longi- 

 tudinal dark bands. The vertebral line is light. The large 

 tubercles near it have dark brown keels. Similar markings 

 are seen on the tail. The head is yellow, dotted or clouded 

 with dark brown. The lower surfaces are yellow, or yel- 

 lowish white, uniform or spotted on the belly, preanal 

 region and thighs, with slate or gray. 



Length to anus 78 85 95 98 100 103 



Length of tail 40 48 3 5 36 42 41 



Snout to ear 14 15 17 17 18 18 



Width of head 27 30 34 35 35 35 



Length of occipital spine 7 8 12 9 12 12 



Fore limb 35 37 42 42 42 44 



Hind limb 43 50 51 52 53 56 



Base of fifth to end of 



fourth toe 13 14 14 15 15 16 



Distribution. — This very distinct species has been found 

 only in southern Arizona and northern Lower California 

 and Sonora, Mexico. 



In Arizona, it has been taken in Cochise (Fairbank), 

 Santa Cruz (Nogales, Madera Canyon, Santa Rita Moun- 

 tains), Graham (Camp Grant), Pima (Tucson, Fort 

 Lowell, foothills of the Catalina Mountains about eight- 

 een miles north from Tucson, Mineral Hill nineteen miles 



