Amphibians and Reptiles of Mexico. 319 



a few were observed on tlie gTound, and tliis wliere tlie timber liad 

 largel)^ been cleared awaj', However, they prefer the more open 

 places, and we Ibund them generali}^ in the clumps of trees on the 

 savannali (Fig. 7), or where the timber had been partially removed 

 on the lowland (Fig. 4). At least at this season, each individual is 

 closely confined to the tree which it has chosen for its home. Diiring 

 tlie two months that vve were in the fiekl there were quite constantly 

 nnder our Observation several trees each of which had its comb lizard 

 occupant, and it was only very rarely that we failed to see the 

 latter wlien we approached the tree. They were frequently observed 

 clinging head upward to the bark on the trunks of the trees, often 

 occupying the same position for honrs at a time. 



As stated above, it may be that in other regions this lizard 

 is more terrestrial in habits, or the difference may be racial, 

 typical acanthura being more terrestrial than completa. In support 

 of the latter explanation it may be significant that the claws in the 

 Cnatotolapam specimens are decidedly shorter than in the acanthura 

 specimens that I have been able to examine, apparently having been 

 worn down by the constant climbing. However, this is not conclusive 

 proof of a racial ditference between the two forms, as a large 

 enough series is not at hand to make it certain that this does not 

 vary in the same form in ditterent regions. The habits shonld be 

 investigated for they will throw light lipon the relationships of the 

 two forms. 



The stomachs exarained contain principally vegetable matter, 

 mostly leaves. A few insect reniains are determinable, but they form 

 only a very small part of the contents. 



Hceloporus imriabills Wiegmann. 



With Ameiva undulata the most common ground lizard on the 

 plains and about Lake Catemaco. 



Our material needs little description as it agrees closely with 

 the descriptions of Boulenger ^) and Stejneger.-) In life the ground 

 color above is dull brownish olive (129, 133, 138, 162), the lateral 

 stripes dull orange yellow (162, 178d), the median stripe pale brownish 

 olive (167, 172), and the light margin of the Shoulder spot light 

 orange or orange yellow (121, 161). As is well known, the stripes 



1) Catalogue of Lizards in the British Museum, Vol. 2, p. 236 — 237, 



2) in: Proc. U. S. nation. Mus., Vol. 14, p. 485—^ 



