The Megalæmidæ, or Barbets, consist of rather small, fruit-eating birds, of heavy ungraceful shape, but adorned with the most gaudy colours, especially about the head and neck. They form a very isolated family; their nearest allies being, perhaps, the still more isolated Toucans of South America. Barbets are found in all the tropics except Australia, but are especially characteristic of the great Equatorial forest-zone; all the most remarkable forms being confined to Equatorial America, West Africa, and the Indo-Malay Islands. They are most abundant in the Ethiopian and Oriental regions, and in the latter are universally distributed.
In the beautiful monograph of this family by the Messrs. Marshall, the barbets are divided into three sub-families, as follows:--
Pogonorhynchinæ (3 genera, 15 sp.), which are Ethiopian except the 2 species of _Tetragonops_, which are Neotropical; Megalæminæ (6 genera, 45 sp.), which are Oriental and Ethiopian; and Capitoninæ (4 genera, 18 sp.), common to the three regions.
The genera are each confined to a single region. Africa possesses the largest number of peculiar forms, while the Oriental region is richest in species.
This is probably a very ancient group, and its existing distribution may be due to its former range over the Miocene South Palæarctic land, which we know possessed Trogons, Parrots, Apes, and Tapirs, groups which are now equally abundant in Equatorial countries.
{ 306}The following is a tabular view of the genera with their distribution:--
--------------------+------------------+----------------+---------------- Genera | Ethiopian | Oriental | Neotropical | Region. | Region. | Region. --------------------+------------------+----------------+---------------- | | | POGONORHYNCHINÆ. | | | Tricholæma 1 sp.|W. Africa | | Pogonorhynchus 12 " |All Trop. & S. Af.| | Tetragonops 2 " | | |Peru & Costa | | | Rica | | | MEGALÆMINÆ. | | | Megalæma 29 " | |The whole region| Xantholæma 4 " | |The whole region| Xylobucco 2 " |W. Africa | | Barbatula 9 " |Trop. & S. Africa | | Psilopogon 1 " | | |Sumatra Gymnobucco 2 " |W. Africa | | | | | CAPITONINÆ. | | | Trachyphonus 5 " |Trop. & S. Africa | | Capito 10 " | | |Equatorial Amer. | | | to Costa Rica Calorhamphus 2 " | |Malay Pen., | | | Sumatra, Borneo| Stactolæma 1 " |W. Africa | | | | | --------------------+------------------+----------------+----------------