42 



ON THE ZOOLOGICAL POSITION OF TEXAS. 



GENEEAL OBSERVATIONS. 



Various important features of tlie fauna of Texas require us to place 

 it within the Xearctic realm ; for although it i^ossesses a number of gen- 

 era which are common to this realm and the ^Neotropical, there are 

 numerous genera which belong to the former exclusively, and very few 

 that belong to the latter alone. In order to display these relations, I 

 place side by side lists of the genera of vertebrates whose geographical 

 relations are in the three directions mentioned. It is assumed for the 

 present that the faunae of Mexico and Central America are branches of 

 the Neotropical. 



Nearctic genera. 



jMised eenera. 



!Xeotropical genera. 



In passing, I give the following list of genera which occupy the ad- 

 jacent regions of the two realms, not extending far into either. Their 

 significance is chiefly to be considered in connection with the minor 



