ART. 6 SOUTH AMERICAN LIZARDS C. E. AND M. D. BURT 19 



Occipital plate at least one-lialf as wide as the breadth of the head; no 

 spiny, pouch-like projection in the region a little posterior to the upper 

 border of the tympanum 3 



2. Posterior tibial scales without prominent projecting spines; supraocular 



scales wider, band-like; caudal crest usually composed of low denticula- 

 tions P. plica (Linnaeus) . 



(Northern South America.) 



Posterior tibial scales with prominent projecting spines; supraocular scales 

 squarish or rounded, not band-like; caudal crest composed of a series of 

 thin, moderately elevated serrations P. stejnegeri, new species. 



(Argentina.) 



3. Occipital plate large, about half as wide as the head P. umbra (Linnaeus). 



(Northern South America.) 



Occipital plate very large, " much broader than half the breadth of the 



head " P. tuberculatum Andersson. 



(Bolivia.) 



PLICA PLICA (Linnaeus) 



1758. Lacerta plica Linnaeus, Syst. Nat., ed. 10, vol. 1, p. 208 (type locality, 



"in Indiis"). 

 1885. Uraniscodon plica Boulengee, Cat. Liz. Brit. Mus., vol. 2, p. ISO. 

 1901. Plica plica Stejnegee, Proc. U. S. Nat. Mus., vol. 24, p. 182. 



Dutch Guiana. — One specimen, No. 11047, collected by C. J. Her- 

 ing in Surinam. 



Trinidad. — Two specimens, Nos. 17727-28, collected by G. .T. 

 Wayman in 1891. 



Venezuela. — Two specimens, Nos. 27798-99, taken at La Guaira 

 by M. W. Lyon and W. Kobinson. 



PLICA STEJNEGERI, new species 



Diagnosis. — Head scales mostly small ; supraoculars not band-like ; 

 occipital plate large, about one-fourth as broad as the breadth of 

 the head ; dorsal and caudal crest moderate, prominent, composed of 

 thin serrations; dorsal and caudal scales imbricate and strongly 

 keeled; posterior tribial scales strongly spinose; two complete and 

 one incomplete gular folds; legs short and heavy. Dorsal ground 

 color gray with brown spots and reticulations, the latter tending to 

 form a series of obtuse chevrons on the back ; throat and upper chest 

 marbled with grayish but not black. 



Habitat. — Argentina. 



Type specimen. — U.S.N.M. Cat. No. 73505; Argentina; Breyer 

 Bros., collectors. 



Description of type specimen. — ^Head moderate, snout short; nos- 

 tril latero-superior, separated from rostral; superciliary edge pro- 

 jecting, angular; upper head scales smooth or tubercular, but not 

 distinctly keeled; two series of interorbitals ; three to five enlarged 

 supraoculars, these more or less squarish or rounded and not occupy- 

 ing over half of the supraocular region; parietals indistinct or 



