SERPENTS. 335 



snakes — ^indeed, of all snakes — the colubers take first rank, num- 

 bering probably fully one-fourth of all known species of Ophidia. 

 They are, strictly speaking, the most cosmopolitan of all the vari- 

 ous groups, and are represented, in addition to genera whose dis- 

 tribution embraces several of the zoogeographical regions, by a 

 number of distinct genera in each of the great zoogeographical 

 regions except Australia, where the family is but feebly developed 

 (Tropidonotus, Coronella). Next in importance, and more strictly 

 tropical, are the venomous colubrine snakes (^Elapidas), with probably 

 upwards of one hundred species, about one-half of which are con- 

 fined to Australia and the neighbouring islands. The family, which 

 is almost wholly wanting in the north temperate region — repre- 

 sented by the genus Callophis in Japan and by the harlequin-snakes 

 (Elaps) in the United States — comprises many of the most deadly 

 of the Thanatophidia, as the cobra (Naja tripudians), Bungarus, 

 and Ophiophagus of India and some of the eastern islands. Callo- 

 phis bilineatus appears to be the only poisonous snake of the Philip- 

 pines. The genus Elaps embraces all or most of the American 

 species of the family, including the much-dreaded Brazilian coral- 

 snake (Elaps corallinus).* 



Partaking very nearly of the distribution of the last family are 

 the burrowing-snakes (Typhlopidse), whose numerous members, 

 belongirg chiefly to the genus Typhlops, are found in nearly all 

 the warmer regions of the earth's surface. One species of the 

 genus, Typhlops lumbricalis, is found in Greece and on some of 

 the Grecian islands. The tree-snakes proper (Dendrophidas) are 

 found in all the tropical regions; the nocturnal tree-snakes (Dip- 

 sadidse) and the arboreal whip-snakes (Dryiophidae) are also essen- 

 tially tropical, but they are either wholly, or almost wholly, wanting 

 in Australia. 



The boas or pythons (Boidae ; Pythonidse) are one of the most 

 distinctively tropical families, comprising some fifty or more species. 

 The pythons proper (genus Python) are distributed throughout 

 nearly the whole of the Oriental region — the islands as well as the 



* Many travellers and naturalists, and notably Maximilian, Prince of Wied, 

 have denied the venomous nature of this animal. The researches of Ihering, 

 however, conclusively demonstrate this nature in Elaps Marcpravii, and would 

 seem, consequently, to uphold the common notion concerning E. corallinus 

 (" Zoologischer Anzeiger," August, 1881). 



