706 & Hans GaDow, 
and Uta and Gerrhonotus. Perhaps Ctenosura ought to be asien 
further Cinosternum but not Chrysemys. 
The “Sonoran” species. 
(List B.) 
Of the 29 Sonorans 2 species only, Gerrhonotus imbricatus and 
Crotalus triseriatus are modified for the cold zone, these alone being 
restricted to above 7000‘, at which level occur 14 in all. 17 species 
extend down to near sealevel, 5°, of which are confined entirely to 
the hot zone and 5 others find their upper level at 4000. The 
Sonorans comprise 16 short-ranged and 13 long-ranged species. To 
the latter belong the 9 species which are entirely or almost confined 
to the Hot zone, whilst no short-ranged species passes beyond 8000‘ 
elevation in marked distinetion from the Nearcties. 
The Sonorans consequently account for most, about two thirds, 
’ ZU S EIO U1273, 
‚ (hiroles canalieu k 
Sceloporus pyrrkoc. 
swuferus 
Phrynosoma asıo 
(nemidopk. unmutabı 
deppei 
Heloderma 
Boa 
Crotalus durissus 
Lachesis 
Uta birarinat 
Scelopor melanork. 
Cnemid. mexican. 
communis 
Scelop. spinosus 
Phrynosom. cormut. 
modestuun 
Scelopor. formosus 
variabüis 
yarronri 
acanthinus 
torqualtus 
Prrynosom. orbicular| 
' Scelop. aeneus 
scalaris 
microlepidot. 
Crotalus horridus 
triserialus 
6errhonotus Uunbric 
List B. 
Showing the vertical distribution or range of Sonoran species. 
Species which attain their unusual toplimit on mountains are marked with a ring: 
The 2 species which have been modified exelusively for the cold zone are indieated 
by double lines. 
