Mr. 0. Salvin un Central- American Birds. 351 



rate Australia, are rather above than below the average brilliancy 

 of their tropical allies. 



We must remember that the tropical fauna almost always ex- 

 tends beyond the geographical tropic, and thus comprehends the 

 largest part of the earth habitable all the year by birds. More- 

 over it is one mass, while the temperate regions are divided; 

 and most important of all, owing to the perennial presence of 

 fruits and insects, a far greater number and variety of birds can 

 exist there than in the colder parts of the earth. It follows, there- 

 fore, that if the proportion of bright- to obscure- coloured birds is 

 the same everywhere, yet the tropics must produce the largest 

 actual number, and it has yet to be shown that this proportion 

 is greater in the tropics. Such extensive tropical families as the 

 Trochilida, Trogonidce, Cotingidce, and Tanagridce, consisting 

 almost entirely of gay-coloured birds, will immediately occur to 

 every one ; but on the other side may be set the Todida, Bp., 

 Thamnophilida, Anabatidcs, Dendrocolaptidce, Capitonidee, and 

 others equally tropical and as remarkable for their generally 

 obscure coloration. 



Here the amount of colour would almost seem to be in inverse 

 proportion to the amount of solar light ; for while no island has 

 more clear sky and bright sunshine than Timor, its birds are far 

 less brilliant than those which dwell amid the gloomy forests and 

 ever-cloudy sky of the Moluccas and New Guinea. 



On the whole, therefore, I cannot but believe that a careful 

 investigation of the facts will show that there exists no imme- 

 diate connexion between tropical heat and light and brilliancy 

 of colour in any department of nature ; and I am sure that on 

 no subject does a greater amount of misconception prevail than 

 on the relative beauty of nature and display of colour in tempe- 

 rate and tropical regions. 

 Delli, Timor, April 20tli, 1861. 



XXX IX. — A List of Species to be added to the Oi-nitliology of 

 Central America. By Osbert Salvin, M.A., F.Z.S. 



The following list of birds is derived partly from a collection 

 brought over by Mr. Robert Owen from Vera Paz, partly from 



