Mexican Amphibians and Reptiles. 697 
12 species remain within the temperate zone, and 9 of them 
are plateau species, while the rest are at home on the western and 
southern slopes of the plateau. 
8 or 9 species belong to the cold zone, natives of the higher 
plateau or of the high mountains. 
Of long-ranged species we can consider 42 species. 
Of these 27 occur near sealevel. 10 of these are tropical (11 if 
Hylodes rhodopis is included) and of them 
4 ascend to 5000‘ 
9... ‚6000 
BE ER R 
1. 
1. 
Of the other 16 species which occur near sealevel, nearly all 
can be shown to have descended into the hot countries from tempe- 
rate or even from the cool zones. 
There are further about 7 species which are centred on the 
plateau, or in the temperate to cool zone, whence they ascend into 
the cold regions; of these Manolepis alone is a Southern, the others 
are Northern genera. 
The rest of the 42 species are made up of such species which 
do not approach sealevel within 1000 to 2000 feet, but which on the 
other hand ascend well. or even far into the cold zone. 
As might be expected, they are rather heterogeneous: 3 southern 
genera are represented by Aylodes palmatus, Hyla eximia and Trimor- 
phodon ypsilon, while 3 other snakes, namely Coronella, Zamenis 
lineatus and Tropidonotus point to the North, besides 2 species of 
Sceloporus. 
Or we may summarise that of the 27 long-ranged species oceurring 
in the Hotlands only 11 have Southern, but 16 Northern affinities. 
Apparently an unexpected result, but another expression of the fact 
that Southern forms are mostly short-ranged. 
The long-ranged species can therefore be arranged into: 
I. Tropical species extending upwards beyond the 3000’ level. 
II. Temperate species descending into the Hotlands and ascending 
into the cold zone. 
III. Species which are restricted to the cool or cold zone. 
Results, which may prove to be of value, derived form com- 
