384 
GEOGRAPHICAL ZOOLOGY. 
[PART IV. 
Family 23.— HYDROPHID^. (8 Genera, 50 Species.) 
General Distribution. 
Neotropical 
SuB-REGIONS. 
Nearctic 
Sub-regions. 
P ala; arctic 
Sub-regions. 
Ethiopian 
Sub-regions. 
Oriental I 
Sub-regions. 
Australian 
Sub-regions. 
3 
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j 
4 
j 1 . 2 . 3 . 4 
j 1 . 2 . 3 . 4 
The Hydrophicke, or Sea Snakes, are a group of 'small-sized 
marine serpents, abundant in the Indian and Australian seas, 
and extending as far west as Madagascar, and as far east as 
Panama. They are very poisonous, and it is probable that many 
species remain to be discovered. The genera are distributed as 
follows : — 
Hydrophis (37 sp.), ranging from India to Formosa and Aus- 
tralia; Platurus (2 sp.), from the Bay of Bengal to New Guinea 
and New Zealand; Aipysurus (3 sp.), Java to New Guinea and 
Australia; Disteira (1 sp.), unknown locality ; Acalyptus (Isp.), 
South-west Pacific ; Enhydrina (1 sp.), Bay of Bengal to New 
Guinea ; Pelamis (1 sp.), Madagascar to New Guinea, New Zea- 
land, and Panama ; Emydocephalus (1 sp.), Australian Seas. 
Family 24.— CBOTALID^. (11 Genera, 40 Species.) 
General Distribution. 
Neotropical 
Sub-regions. 
N EARCTIC 
Sub-regions, 
Pal^arctic 
Sub-regions. 
Ethiopian 
Sub-regions. 
Oriental 
Sub-regions. 
Australian 
Sub-regions. 
1 . 2 . 3 . 4 
1 . 2 . 3 . 4 
1 
3.4 
— 
1 
1 . 2 . 3 . 4 
j 
The Crotalidse, or Pit Vipers, including the deadly Rattlesnakes, 
form a well-marked family of fanged serpents, whose distribu- 
tion is very interesting. They abound most in the Oriental 
region, at least 5 of the genera and 20 species being found within 
its limits, yet they are quite unknown in the Ethiopian region 
- — a parallel case to that of the Bears and Deer. A few species 
are peculiar to the eastern portion of the Palsearctic region, while 
