1919] Dickerson, Diagnoses of New Species and a New Genus of Lizards 403 



crest;' width of the whorl (2 rows dorsally) equal to distance between nostril and 

 anterior angle of orbit; base of 5th to end of 4th toe equal to distance from anterior 

 ear to nostril; femoral pores, 5-6. Color light yellowish, with gular region, breast, 

 and arms black ; short transverse bar of black posterior to points of arm insertion (its 

 anterior margin about on line of axillas), connected at ends with narrow longitudinal 

 straight lines of black forming a square open on anterior side, containing black spot at 

 center on crest ; a second black bar crosses back posterior to this, curving downward 

 and backward to meet black of breast. 



Measurements of the Type. — Total length, 608 mm. + ; tip of muzzle to 

 anus, 295; tail, 313 + (reproduced); tip of muzzle to fold; 113; tip of muzzle to 

 posterior border of ear, 84; anterior border of ear to nostril, 62; head width, 74; hind 

 leg, 166; base of 5th to end of 4th toe, 62. 



The largest females in the collection measure only two-thirds the length of the 

 large males; the crest is very low, ending about the middle of the body, the foot has a 

 proportionate length as in the large males but the head is smaller and shorter (so 

 that length from base of 5th to end of 4th toe greatly exceeds distance from anterior 

 ear to nostril); the enlarged scales of the caudal whorls are smaller; the general 

 coloration is darker and the color pattern retains the transverse light bands, or 

 series of spots (7 between rump and axilla) of the immature. 



Measurements of No. 5641 9 . — Total length, 471 ; tip of muzzle to anus, 191 ; 

 tail, 280; tip of muzzle to fold, 62; shielded part of head, 43; head width, 38; head 

 width across middle of orbits, 25; axilla to nostril, 74; axilla to anterior border of 

 ear, 42; width of widest caudal whorl, 10; hind leg, 120; base of 5th to end of 4th 

 toe, 47. 



3. Sauromalus interbrachialis, 1 new species 



Type.— A. M. N. H. No. 6809. Collector, C. H. Townsend, Albatross Expedi- 

 tion, March 27, 1911. 



Paratype. — A. M. N. H. No. 6808 (immature). 



Type Locality. — La Paz, Lower California, Mexico. 



Diagnosis. — Size medium, 280 mm. total length of largest specimen known 

 (U. S. N. M. No. 12633) ; nuchal scales smooth, not as large as the largest head scales, 

 scarcely larger than the supraoculars ; very much smaller than the largest preauricular 

 scale; scales on post auricular folds tubercular, not greatly enlarged; dorsal scales 

 relatively smooth, small, from 26 to 30 in a head length; ventral scales from gular fold 

 to anus, 133; femoral pores, 14. Color tawny brown sprinkled evenly with small dark 

 spots everywhere dorsally and laterally between nape and tail, less conspicuously on 

 dorsal surfaces of legs, on the breast and gular region, and below the lateral fold to 

 the groin; a double dark bar over the back between the arms, with faint indications 

 of a similar double bar anteriorly and three posteriorly. 



Measurements of the Type. — Total length, 250 mm. ; length of head and body 

 to anus, 129; tail length, 130; tip of muzzle to posterior border of ear, 30, to gular 

 fold, 46; head width, 27; hind leg, 74; hind foot, 31; base of 5th to end of 4th toe, 23. 



The medium-sized chuck walla collected in 1882 by L. Belding on 

 the island of Espiritu Santo is Sauromalus interbrachialis (U. S. N. M. 



'With reference to the double dorsal bar between the arms. 



