MIMICRY 1597 



usually olive-green or brown. It is a very common 

 thing to find species of the Mimeta resembling 

 Tropidorhynchi living on the same island. 



The Tropidorhynchus bouruensis and Mimeta 

 bouruensis are both found in the island of Bouru, 

 the latter of which mimics the former as described 

 by Mr. Wallace: 



"The upper and under surfaces of the two birds 

 are exactly of the same tints of dark and light brown. 

 The Tropidorhynchus has a large, bare, black patch 

 round the eyes; this is copied in the Mimeta by a 

 patch of black feathers. The top of the head of the 

 Tropidorhynchus has a scaly appearance from the 

 narrow scaly-formed feathers, which are imitated 

 by the broader feathers of the Mimeta, having a 

 dusky line down each. The Tropidorhynchus has a 

 pale ruff, formed of curious recurved feathers on the 

 nape (which has given the whole genus the name of 

 friar birds) ; this is represented in the Mimeta by a 

 pale band in the same position. Lastly, the bill of 

 the Tropidorhynchus is raised into a protuberant 

 keel at the base, and that of the Mimeta has the 

 same character, although it is not a common one in 

 the genus." The result is that when superficially ex- 

 amined the birds seem to be identical, though pos- 

 sessed of important structural differences, and placed 

 wide apart in any natural arrangement. 



Mr. Wallace mentions some curious cases of 

 mimicry among reptiles, where a venomous tropical 

 genus of snakes, Elaps, belonging to America, is 

 closely mimicked by several genera of harmless 

 snakes. 



