The Beaded Lizards 



of incubation. Of the batch obtained half of them were placed 

 in damp sand and exposed to the sun. The other half was 

 buried in dry sand and likewise placed in the sunlight. The 

 eggs that were kept damp hatched within a period of from twenty- 

 eight to thirty days. Those placed in the dry sand shrivelled 

 into small, hard and shapeless masses. 



Upon first hatching the youngsters were of stout appearance 

 and about four inches long. Their colours were more vivid 

 than those of the adults. 



Mr. Ralston further informs me that he examined some 

 of the freshly laid eggs and found them to contain minute but 

 well-formed embryos. 



THE MEXICAN BEADED LIZARD "ESCORPION" 

 Heloderma horridum, (Wiegmann) 



In form, this heavy-bodied lizard is very similar to the pre- 

 ceding species, though the tail is considerably longer in propor- 

 tion to the creature's length. 



Colouration. The general pattern and colours are quite 

 different from the Gila Monster. The upper and lower surfaces 

 are black or dark brown, with scattered spots and blotches of 

 rich yellow. With the majority of specimens, the black pre- 

 dominates, and with many specimens the yellow is confined to 

 single, scattered tubercles. The bead is usually uniform black.* 



With young individuals the tail is broadly and vividly 

 ringed with yellow, a character that appears to give way with 

 maturity to narrow and broken rings. Young specimens are 

 jet black, with vivid yellow markings. The older specimens 

 show a brownish body colour, while the yellow is rather dull 

 and not sharply defined on many. Although the writer has 

 examined over fifty specimens of this species before compiling 

 this description he has not noted a suggestion of the peculiar 

 pinkish shades so often seen with the Gila Monster. 



Dimensions. The Mexican Beaded Lizard attains a larger 

 size than the species inhabiting the United States. Following 

 are the measurements of an adult specimen, from Guerrero, 

 Mexico: 



* An important character of differentiation from the Gila Monster 

 with which the head is generally well blotched with the lighter hue. 



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