174 
None of the tropical species extend into this zone ; and, although 
it is not improbable that a future traveller may discover the presence 
of Batrachians, their number will be very limited. The first of the 
species mentioned offers another example of the occurrence of northern 
forms in the Himalaya, the genus Phrynocephalus having its range 
over High Asia to the shores of the Caspian Sea and to Siberia; the 
species is said to be found also in Affghanistan. Barycephalus and 
Biancia are peculiar to the Himalaya, and the former bears a striking 
resemblance to Microphractus of the Andes of Ecuador: in fact, 
they do not differ in any essential external character, and would 
be referred to the same genus if it were not for the dentition. A 
single Tree-lizard enters this zone (Calotes minor), replacing Calotes 
tricarinatus of the temperate zone, but it is of small size, and the 
bright green colour of other species is changed to a dull yellowish, 
marbled with brown. Finally, the only species of Snake (Spzlotes 
hodgsonii) is a representative of Indian forms—namely, of Sp. reti- 
culatus from the temperate zone, and of Sp. melanurus from the 
lowlands. 
Thus, although the forms of this zone are specifically distinct 
from those without the limits of the Himalaya, its Amphibio-fauna 
is mixed, and composed partly of species which approach northern 
or southern forms, and partly of others quite peculiar to those moun- 
tains. 
In conclusion, it will be of interest to make a comparison of the 
greatest elevations at which Reptiles have been found in different 
parts of the globe. In the Alps and in the Andes the Batrachians 
ascend to much greater heights than Lizards or Snakes, whilst in 
the Himalaya these latter appear to go higher ; a discrepancy, how- 
ever, which may arise from our present incomplete knowledge, as it 
is very probable, in my opinion, that some species of Toad or Sala- 
mander will be discovered at a greater altitude than the specimens 
of Bufo vulgaris from the Collection of Messrs. v. Schlagintweit. 
Bufo vulgaris and Salamandra atra live in the Alps at 6000 feet, 
Rana temporaria round lakes, near the region of eternal snow 
(8500 feet), which are nine months covered with ice; Triton at 
7800 feet in the Pyrenees. Castelnau* found a Tree-frog at nearly 
15,000 feet (English) in the Andes, and Tschudi+ Leiuperus viri- 
dis (a species little known) near the region of eternal snow at 16,000 
feet. With regard to Snakes, the occurrence of Spilotes hodgsonii 
at 15,200 feet in the Himalaya gives the highest point at which - 
an Ophidian has ever been found; for Vipera berus and Tropido- 
notus natriz reach to 6000 feet only in the Alps, and the former to 
7000 feet in the Pyrenees ; Castelnau states that he met with two 
Snakes only at 7500 feet in the Andes. The Lizards rise still higher: 
three species of them live at 15,300 feet in the Himalayas. The state- 
ments as to the altitudinal extent-of our European species are scanty: 
Zootoca vivipara is known to rise in the Austrian Alps to 3500 feet, 
and Anguis fragilis to 5000. Castelnau merely observes that 
* Comptes Rendus, xxyi. p. 101. tT Tschudi, Faun. Peruan. Herpetol. p. 68. 
