Affin ity of the North- A merica n L iza rd- Fa una. 25 



as to the nou-neotropical character of the North-American 

 Lacertilian fauna, as set forth in ray ' Geographical and Geo- 

 logical Distribution of Animals ' and elsewhere. Mr. Bou- 

 lenger quotes the following paragraph from the work above 

 mentioned : — " M. Boulenger has recently attempted to show 

 (Ann. & Mag. Nat. Hist. August 1885) that the Nortli- and 

 South-American Lacertilian faunas are, strictly speaking, 

 one, the Neogean, a conclusion which is not borne out by the 

 facts of distribution. The misconception arises from the 

 incorporation of the tract lying south of the line indicated 

 above [a line drawn from San Francisco to Galveston, in 

 Texas] with the North-American faunal region proper, while 

 in reality it is a transition-tract more nearly Neotropical in 

 character than Nearctic." 



" What the facts are," Mr. Boulenger then continues to 

 say, " 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,^ and of the glass snake {Ophisaurus).'" 



The facts relating to the question in point are fully set 

 forth in my paper on " The Value of the ' Nearctic ' as one 

 of the Primary Zoological Regions," published in the ' Pro- 

 ceedings of the Academy of Natural Sciences of Philadelphia ' 

 for 1882 (pp. 331, 332), to which reference is made in the 

 preface of my work on distribution. An analysis of the 

 families and species of the North-American Lacertilian fauna 

 there given shows two facts very distinctly, which I have 

 stated as follows : — 1. The South-American (Neotropical) 

 forms of Lacertilians — Teida^j Iguanid*, Anolida3 — ^io^almost 

 immediately on the borders of tlie Nearctic region, sending 

 but an extremely limited number of representatives beyond 

 the Sonoran subregion [the transition-tract] ; and 2. The 

 very great paucity of Lacertilian forms in general throughout 

 the great mass of the North- American continent. Excluding 

 the Sonoran and Californian provinces, and the immediate 

 border-line of the region, there would appear to be in all hut 

 about twenty species of Nearctic Saurians, thirteen of which, 

 helong to the Old- World genus Eumeces ! The most widely 

 diffused form of North-American Eumeces^ moreover, is a 

 Paliearctic species * ! A further relationship with the Palae- 

 arctic fauna is maintained by Ophisaurus^ the only New- 

 World representative of the glass snakes. 



The range of a few species has been extended since the 

 above analysis was formulated ; but the facts stand substan- 

 tially as stated, and fully bear out the general conclusions of 



* More recently separated as a distinct species by B.julenger. 



