12 



BULLETIN 154, UNITED STATES NATIONAL MUSEUM 



both genera in the former genus shows that he recognized no differ- 

 ences between them and, although later workers have noted the dif- 

 ferences that are considered significant here, a greater or lesser 

 number of the forms of each genus has been placed in the other until 

 the present time. Even the type species of Cnemidophorus^ murlnus^ 

 was not designated as such until the appearance of the Systema 

 Reptilium of Fitzinger in 1843. 



The chief distinction thus far advanced for the separation of 

 Cncmidopliorus from Ameiva, no doubt its closest relative, has been 

 based upon the character of the scaly portion of the tongue. Cnenu- 

 dopJiorus has been said to have an arrow-headed or heart-shaped 

 tongue, the scaly portion being distinctly divided behind, and the 



Figure 1. — Diagram showing the tongue characters of tytical Cnemidophorus 



(LEFT) and typical, AmEIVA (RIGHT). NOTE THE POSTERIOR BIFURCATION OF THE 



TONGUE OF Cnemidophorus and the presence of a sheath between the 



TONGUE AND LARYNX OP AMEIVA 



corresponding part of the tongTie of Ameiva has been said to be 

 undivided, the scaly portion being entire and rounded as in the 

 present type species of the genus, Ameiva ameiva ameiva. The forms 

 admitted to Cnemidophorus, even by supposedly incorrect diagnoses, 

 all show a greater or lesser degree of posterior fission of the scaly 

 portion of the tongue, and are in this regard correctly placed. More- 

 over, many of the recognized Ameivas, which possess from eight 

 to ten longitudinal rows of enlarged ventral scutes are also found to 

 present this condition. Therefore, it seems significant that Ameiva 

 taeniura (M. C. Z. No. 25535) from Hispaniola possesses a very 

 markedly heart-shaped tongue, and that Cope (1894) described 

 C nemidophorus amivoides from a typical specimen of Ainciva- nn- 

 dulata (A. M. N. H. No. 16316) with less posterior bifurcation of 



