14 BULLETIN 15 4, UNITED STATES NATIONAL MUSEUM 



The writer (1929) has already })re.seiiteil his argument for the 

 union of Verticaria, described by Cope (1809), Avith Cneinidophorus. 

 It Avas found that the single frontoparietal plate of the Verticaria 

 section is subjected to considerable variation, being sometimes eom- 

 l^letely divided as in (^ nemklojyhorus^ and hence not wholly reliable 

 as a diagnostic ciiaracter. Also, the large ccralbensis, which had 

 been assigned to Verticaria by Van Denbnrgh and Slevin (1921), 

 was found to be an apparent derivative from the tessellatus group 

 of Cnemidophoi'UH^ whereas the small T'. lnjperythra was found to be 

 an obvious derivative from the sexlineatus group. Thus, the un- 

 reliable nature of the sole generic distinction, and the divided affini- 

 ties existing in the supposed entity itself, rendered Verticaria 

 untenable. 



The following key is thought to be sufficient to separate the genus 

 Cvcm'/dophoniJi, as here constituted, from its nearest relatives. 



KEY TO CNEMIDOPHORUS AND AM.IKD GENERA 



1. Hind foot with five well developed toes 2. 



Hind foot witli on'.y four well-developed toes, fifth a mere vestige Teius. 



(Confined to southern South America.) 



2. Lateral and posterior teeth compressed longitudinally so as to be longer 



than wide 3. 



Lateral and posterior teeth compressed transversely so as to be wider 



than long Dicrodon. 



(Confined to western South America.) 



3. Scaly portion of tongue bifid posteriorly, arrow-headed or heart-shaped 



in outline 4. 



Scaly portion of tongue not bifid posteriorly, not arrow-headed or heart- 



i^ihaped in outline Ameiva. 



( Southern South America, northward to Mexico ; and the West Indies, 

 northward to Cuba and the Bahama Islands.) 



4. Sheath not noticeably developed between larynx and scaly portion of the 



tongue; dermal fold usually absent at sides of base of tongue. 



Cnemidophorus. 

 (Southern Brazil and Bolivia, northward to Oregon, Wisconsin, and 

 Maryland, exclusive of the West Indies.) 

 Sheath developed between larynx and scaly purtiou of tongue: dermal fold 



present at sides of base of tongue Ameiva. 



( Southern South America, northward to Mexico ; and the AVest Indies, 

 northward to Cuba and the Bahama Islands.) 



Diagnosis. — The genus Gneinidoplwrus belongs to the family 

 Teiidae and may be diagnosed as follows : Tongue long, narrow, 

 deeply bifid anteriorly, bilobate or heart-shaped posteriorly, and not 

 retractile into a basal sheath; lateral and posterior teeth compressed 

 longitudinally, bi- or tri-cuspid; anterior teeth simple, usually con- 

 ical; head covered with large, regular shields, except occipitals or 

 nuchals, which are small and irregular; back and sides covered with 

 small, smooth, granular scales; ventral plates smooth, arranged in 



