384 



GEOGRAPHICAL ZOOLOGY. 



[part IV. 



Family 23.— HYDROPHID^. (8 Genera, 50 Species.) 



General Distribution. 



Neotropical 

 Sub-regions. 



Nearctic 

 Sub-regions. 



Pal^arctic I Ethiopian I Oriental 

 Sub-regions. Sub-regions. Sub-regions. 



Australian 

 Sub-regions. 



3 I 4 1.2.3.41 1.2.3.4 



The Hydrophidee, 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 (1 sp.), 

 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.— CROTALID^. (11 Genera, 40 Species.) 



General Distribution. 



Ethiopian 

 Sub-regions. 



Oriental 

 Sub-regions. 



1.2.3.4 



Australian 

 Sub-regions. 



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 



