464 Bulletin American Museum of Natural History [Vol. XLI 



No. 12633; Belding, 1887, West American Scientist, III, p. 97; 

 Stejneger, 1891, Proc. U. S. Nat. Mus., XIV, p. 409). It is a somewhat 

 larger, older specimen than the type from La Paz. 



Belding's specimen from Espiritu Santo, examined through the 

 courtesy of Dr. Stejneger, measures 280 mm., total length; 183, 

 tail length; it has 139 ventral scales from gular fold to anus, and 26 

 dorsal scales in a head length; femoral pores, 15. 



4. Sauromalus townsendi, 1 new species 



Type.— A. M. N. H. No. 5643, d" Collector, C. H. Townsend, Albatross 

 Expedition, April 12, 1911. 



Type Locality. — Tiburon Island, Gulf of California, Mexico. 



Diagnosis. — General resemblance to S. ater Dumeril but with coarser scutella- 

 tion throughout, especially on extremities. Size medium, length of type (adult, 

 but probably not full-grown; also tail reproduced) 302 mm.; dorsal scale rows in 

 head length, 28; ventrals from gular fold to anus, 125; number of scales around 

 thick part of tail, 80-90; femoral pores, 14. Coloration yellowish, with head, should- 

 ers, brachials, gular region, and anterior breast, also lumbar region and hind legs 

 dorsally and ventrally, very dark brown, and an irregular freckling of the same 

 color dorsally and ventrally over the yellow between. 



Measurements of the Type. — Total length, 302 mm.; head and body to anus, 

 166; tail, 125+ (reproduced); tip of muzzle to posterior border of ear, 39, to gular 

 fold, 55; head width, 36; hind leg, 100; hind foot, 46; base of 5th to end of 4th toe, 

 34. 



This is possibly the species reported by L. Belding from Guaymas in 

 1887 (West American Scientist, III, p. 97). Its resemblance to S. ater 

 Dumeril may signify connection with that species in Sonora in 

 former times if not to-day. 



5. Sauromalus varius, new species 



Type.— A. M. N. H. No. 5633. Collector, C. H. Townsend, Albatross Expedi- 

 tion, April 13, 1911. 



Paratypes.— A. M. N.H. Nos. 2698-2702, 5026, 5610-5632, 5634-5638, 5706- 

 5708. 2 



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



Common Name. — Piebald Chuckwalla. 



Diagnosis. — Size very large, sometimes exceeding 600 mm.; nuchal scales 

 somewhat enlarged medially, smaller than largest head scales and preauricular 

 scales, with only faint tendency to formation of spines posteriorly; postauricular 

 scales small; dorsal scales smooth, median subquadrangular, lateral with tendency to 



'Named in honor of C. H. Townsend, leader of the Albatross Expedition, 1911. 

 2 Three additional specimens are mounted and on exhibition in the Lower California Habitat 

 Group of lizards, and A. M. N. H. No. 2701 has been made into a study skeleton. 



