308 UE. H. GADOW ON EVOLUTION [Mar. 20, 



C HYPER YTHRUS Oope = se?'ice« van Denlmrgh = beldingi Cope. 



4 supraoculars. 



Collar composed of large scales, without granules ; the figure 

 in Cope's posthumous work does not agree with his description, 

 nor with the specimens in the British Museum. 



Posterior surface of forearm with very slightly enlarged 

 granules. 



Femur with 6 irregular rows of scales. 



Pores 16 to 17. 



Length, a gravid specimen, 59 mm. ; another 60 mm. 



Range from Diego County in California apparently through the 

 Mdiole of Lower California to Cape San Lucas, including Cedros 

 Island, and the Island of )San Jose in the Gulf, 



Coloration of under parts all white, mth a slight blue tinge on 

 the abdomen iii the male. Upper parts striped, without any 

 field-spots. In a female specimen (Bi-it. Mus.) the striation is the 

 same as that of a C. sexlhieatus from San Diego ; there are three 

 pairs of complete stripes with a faint central stripe. In a male 

 specimen the third pair converges from the head backwards, 

 forming an unj)aired stripe from midback to tail ; a imique case 

 amongst Cnemidopliorus with only 5 to 6 stripes, the third pair 

 universally enclosing a broad mid-field. In the triangular short 

 mid-field of this specimen is a very short whitish-grey faint mid- 

 stripe from the head to the neck ; fields uniformly dai'k grey to 

 black. 



In most of its characters C. hyperythrus very closely approaches 

 C. sexUneatus, which also occurs in Diego County. 



Definition. — Cnemidophorus with normally 3 supraoculars 

 (about 10 per cent, with 4); collar composed of enlarged scales in 

 several rows ; posterior surface of forearm covered with granules. 



This group is restricted in Mexico to the Atlantic and Pacific 

 Tierra caliente, and contains three well-definable forms. 



Small, exceptionally iip to 80 mm. in length, sharply marked with 

 7-11 pale stripes. Abdomen of adult male black. Collar and 

 rest of under parts of female white : C. dejrpei (text-figs. 71 and 

 72). — From coast of Jalisco and Vera Cruz in the Tierra caliente 

 inland up to 2000 feet, southwards through Central America 

 (Nicaragua, Costa Rica) to Caracas in Venezuela. Concerning 

 Island of Cozumel, see p. 316. 



Larger, up to 138 mm. Collar of both sexes black, in contrast 

 with throat and chest. Abdomen whitish, chequered with blue : 

 C. guttaUts. 



A. Throat pale, whitish. Back with conspicuous white stripes 

 on very dark ground, or the stripes are broken up into 



