346 On the Affinity of the North- American Lizard-Fauna. 



What the facts are that do not bear out my conclusion the 

 author omits to state, unless they be the presence of the " Old- 

 World genus of skinks, Eumeces " (p. 316) and of the glass 

 snake {Ophisam-us). With the latter 1 have dealt in the 

 essay referred to, and shown that the Anguidge, of which 

 family Ophisaurus is a member, are essentially American, 

 reaching their fullest development in Central America ; that 

 they are well represented in North and South America, and 

 occur in two genera and three species in the Paleearctic region ; 

 and that if the affinity between Ophisaurus and Pseudopus 

 is great, that between Anguis and the South- American 

 OpModes is scarcely less. The idea that Eumeces is an Old- 

 World genus is erroneous. As now characterized it embraces 

 thirty-one species, of which twenty-one are American (only 

 half that number extending north of Mr. Heilprin's line)j 

 nine Old- World, and one of unknown habitat. But, far 

 better than any discussion, the following list of the few Lacer- 

 tilia of British Columbia (a district well beyond the debat- 

 able area and also the northernmost point reached by lizards 

 in North America) will answer Mr. Heilprin's criticism, in 

 showing that even so far north that part of the fauna is 

 purely Neogean. 



Lacertilia of British Columbia * 



Iguanid^ 



1. Scelopoms gratiosus. 



2. undulatus. 



8. Phrynosoma Douglassii. 

 4. cornutum. 



Anguid^ . . 5. Gerrhonotus ccet'uleiis. 

 SciNCiD^ . . 6. Emneces Skiltonianus. 



All four genera attain their greatest development south of 

 Mr. Heilprin's line. 



A list of the lizards of any northern district of the United 

 States would equally well support my view. Indeed I can 

 only repeat my statement (/. c. p. 80), that the North- 

 American lizards constitute no essentially distinct fauna, but 

 are merely an offshoot of that of Central America. 



* Cf. J. K. Lord, Brit. Columb. ii. pp. 302, 307, and 308. 



