The Psammophidæ, or Desert Snakes, are a small group characteristic of the Ethiopian and Oriental regions, but more abundant in the former. The distribution of the genera is as follows:—
Psammophis (16 sp.), ranges from West Africa to Persia and Calcutta; Cœlopeltis (1 sp.), North and West Africa; Mimophis (1 sp.), Madagascar; Psammodynastes (2 sp.), Sikhim to Cochin China, Borneo and the Philippine Islands; and Dromophis (1 sp.), Tropical Africa.
Family 10.—RACHIODONTIDÆ. (1 Genus, 2 Species.)
| General Distribution. | |||||
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| Neotropical Sub-regions. | Nearctic Sub-regions. | Palæarctic Sub-regions. | Ethiopian Sub-regions. | Oriental Sub-regions. | Australian Sub-regions. |
| — — — — | — — — — | — — — — | — 2. 3 — | — — — — | — — — — |
The Rachiodontidæ are a small and very isolated group of snakes of doubtful affinities. The only genus, Dasypeltis (2 sp.), is confined to West and South Africa.
Family 11.—DENDROPHIDÆ. (7 Genera, 35 Species.)
| General Distribution. | |||||
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| Neotropical Sub-regions. | Nearctic Sub-regions. | Palæarctic Sub-regions. | Ethiopian Sub-regions. | Oriental Sub-regions. | Australian Sub-regions. |
| 1. 2. 3. 4 | — — — — | — — — — | 1. 2. 3. 4 | 1. 2. 3. 4 | 1. 2 — — |
The Dendrophidæ, or Tree Snakes, are found in all the Tropical regions, but are most abundant in the Oriental. The genera are distributed as follows:—
Dendrophis ranges from India and Ceylon to the Pelew Islands and North Australia, and has one species in West Africa; Ahætulla is almost equally divided between Tropical Africa and Tropical America; Gonyosoma ranges from Persia to Java and the Philippines; Chrysopelea is found in India, Borneo, the Philippines, Amboyna, and Mysol; Hapsidrophis and Bucephalus are confined to Tropical Africa; and Ithycyphus (1 sp.), is peculiar to Madagascar.
Family 12.—DRYIOPHIDÆ. (5 Genera, 15 Species.)