CHAP. XIX,] 



REPTILES, 



379 



and the Indian Peninsula ; and Lawjalui (2 sp,), confined to 

 Madagascar. 



Family 13.— DIPSADID.i:. (11 Genera, 45 Species.) 



The Dipsadidtp, or Nocturnal Tree Snakes, are di.gtinguished 

 from tlie hast feniily by their dark colours and nocturnal habits. 

 They are about equally abundant in the Oriental and Neotropical 

 regions, less so in the Ethiopian, while only a single species 

 extends to North Australia. The following are the best known 

 genera : — 



Dipsas, comprising all the Oriental species with one in Asia- 

 Minor, and a few from the Moluccas, New Guinea, North Aus- 

 tralia, West Africa, and Tropical America; Thamnodyastes, 

 Troindodlpsas, and several others, from Tropical America; Dipsa- 

 doloa, from West Africa and Tropical America ; Leptodeira, from 

 Tropical and South Africa, South America, and ]\Iexico ; and 

 Pytlwnodipsas, from Central Africa. 



Family U.— SCYTALID.F. (3 Genera, 10 Species.) 



It is doubtful how far the three genera which constitute this 

 family form a natural assemblage. We can therefore draw no 

 safe conclusions from the peculiarity of their distribution — 

 Bcytah and Oxyrlwpus being confined to Tropical America ; 

 while Hologcrrlium inhabits the Philippine Islands. 



