The Plated Lizards and Snake-like Species 



in founding new species and sub-species upon variations thaf 

 are of little importance. There has been a number of species 

 described as occurring in the United States and the descriptions 

 of them have been based upon slight differences of scalation and 

 distribution. If these obscurely different specimens were mixed 

 among varying individuals of the really staple species and the 

 locality labels removed, it is doubtful if the observers of their 

 "distinctly" different characters could pick them out again. 

 Thus it appears that the different species described as occurring 

 in the United States must simmer down to four, a key of which 

 is herewith presented: 



I. Three shields arranged in triangular fashion, in front of 

 the large shields between the eyes. 



Scales of the back and the sides strongly keeled. 



KEELED LIZARD, G. multicarinatus. 



Habitat. Widely distributed. The Pacific Coast 



region, from British Columbia to Central America. 



Scales on the back strongly keeled; those of the sides 



smooth. BROWN LIZARD, G. liocephalus. 



Habitat. Texas and Mexico. 



Scales of the back feebly keeled; those of the sides 

 smooth. KING'S LIZARD, G. kingii. 



Habitat. Arizona, New Mexico, western Texas and 

 northern Mexico. 



II. Three pairs of shields in front of the large shields between 

 the eyes. 



Scales of the back keeled; those of the sides smooth. 



PLATED LIZARD, G. imbricatus. 

 Habitat. Western Texas ; Mexico. 



Detailed descriptions of these species follow: 



THE KEELED LIZARD 

 Gerrhonotus multicarinatus, (Blainv.) 



Slender in form, with very long and gradually taper- 

 ing tail. The scales of the upper surfaces are very strongly 

 keeled, particularly on the back and top of the tail. The 

 scales of the abdomen are oblong in shape and highly pol- 

 ished; they are arranged in the same ring-like formation as 

 those above. 



Colouration. Above, the colour is brown or olive, with 

 numerous dark and wavy cross-bands, many of which are bor- 

 dered with white spots. The soft strips of skin on the sides 



