INTRODUCTION 
A Cuecx List of South American lizards is much needed by 
students of herpetology, since there is no comprehensive reference 
work dealing with these forms. Boulenger’s “Catalogue of the 
Lizards in the British Museum” (1885-1887) is very valuable for 
the species described prior to its appearance. This present list has 
been assembled upon the plan adopted by Stejneger and Barbour 
(1917 and 1923) for the two editions of their Check List of North 
American Amphibians and Reptiles, which in turn was patterned 
after the American Ornithologists Union Check List of Birds. 
Much of the present check list has been prepared from biblio- 
graphic records copied from our recent contributions entitled “The 
South American Lizards in the Collection of the American Museum 
of Natural History” (Bull. Amer. Mus. Nat. Hist., Vol. 61, Art. 7, 
1931, pp. 227-395, figs. 1-15), and “The South American Lizards 
in the Collection of the United States National Museum” (Proc. 
U. S. Nat. Mus., Vol. 78, Art. 6, 1930, pp. 1-52), respectively, but 
it is only through a continued systematic search and analysis of 
the literature that we have been able to bring the enterprise to 
completion. Although we are personally inclined to be conservative 
in our estimate and recognition of species, we offer this present 
work with the full realization that we have listed too many, rather 
than too few, of the named forms. In other words, it is perfectly 
clear to us that great systematic modifications of the present ar- 
rangements must ultimately be made by students of South American 
lizards. Thus, while certain genera are obviously full of synonyms, 
a number of new species and subspecies must undoubtedly remain 
to be found. 
The arrangement used here is as follows: the families are given 
in phylogenetic or systematic sequence and the smaller groups are 
in alphabetical order. Well known synonymies are not included 
under the various forms for the citations of these are common in 
the general herpetological literature. However, a considerable num- 
ber of new synonymies, which are proposed and supported by us. 
in our contribution based upon the South American lizards in the 
collection of the American Museum of Natural History (or in other 
manuscripts) are listed below in their proper places; also, it may 
be stated that the present use of certain new generic and subspecific 
IV 
