474 Bulletin American Museum of Natural History [Vol. XLI 



bordered anteriorly with black; the mottling with orange-brown and black extends 

 over sides of head; the throat is crossed by 2-3 narrow bars of intense black; mid- 

 ventral caudal line marked by a double series of small black spots. 



The immature of this species is black everywhere ventrally; black also on the 

 sides, brown on the back, with closely set pin-points of orange-yellow, verging to white 

 laterally, on exposed surfaces of body and extremities; head and tail unspotted and 

 lighter in general coloration; an unspotted mid-dorsal area, broad on nape and nar- 

 rowing to a point opposite the elbows. 



Measurements of the Type. — Total length (tail broken off 30 mm. from base, 

 with regeneration just begun); head and body to anus, 87 mm.; end of muzzle to 

 collar, 30; tip of muzzle to anterior ear, 20; greatest head width, 12, across anterior 

 angle of orbits, 8.5; hind leg, 54; base of 5th to end of 4th toe, 23.5. 



Measurements of No. 6884. — Total length, 144 mm.; head and body to 

 anus, 42; tail length, 102; tip of muzzle to posterior gular gold, 17, to anterior ear, 12, 

 to interparietal, 9, to fore limb, 18; greatest head width, 7, width across posterior 

 supraoculars, 6; collar to anus, 25; hind leg, 28. 



It would seem likely from the discovery of this rare species on 

 Tiburon Island with immature very like the type of C. martyris Stej- 

 neger, 1891, that the latter species was described from immature forms 

 only. The different general coloration in the two, lack of enlarged 

 scales on the ventral aspect of the forearm of martyris, and the variation 

 in corresponding measurements of C. martyris and the paratype of C. 

 disparilis indicate that the species are distinct — as we should expect as 

 a result of development of forms isolated on the two widely separated 

 islands, Tiburon and San Pedro Martir, in a region unfrequented 

 by man. 



20. Cnemidophorus estebanensis, new species 



Type.— A. M. N. H. No. 5571. Collector, C. H. Townsend, Albatross Expedi- 

 tion, April 13, 1911. 



Type Locality. — San Esteban Island, Gulf of California, Mexico. 



Diagnosis. — Bearing close resemblance to C. melanostethus Cope and C. puncti- 

 linealis, new species, but very greatly more elongated than the latter for a given girth 

 and development of color pattern, and with longer head and foot measurement than 

 the former. It differs from punctilinealis in having the scales on the underside of 

 the forearm considerably enlarged, the dorsal granules smaller, more elongated, set 

 closer together (4 instead of 2% to a millimeter). It differs from both in the small 

 size and large number of rows of brachials and femorals, 8 and 8 respectively. 



Measurements of the Type. — Total length, 175 mm. + (tail reproduced); 

 head and body to anus, 76.5; tail length, 98.5 + ; tip of muzzle to collar, 26, to anterior 

 border of ear, 19; greatest head width, 11; hind leg, 55; base of 5th to end of 4th 

 toe, 26. 



C. melanostethus (A. M. N. H. No. 2525 from Tucson. Collector, M. C. Dicker- 

 son, 1912), with equal head and body length, has head length to fold, 25 mm., to 

 anterior border of ear, 17, and length of 4th toe from base of 5th, 23.5 mm. 



