ix WARNING COLORATION AND MIMICRY 261 



is a group of Curculionidse, forming the genus Pachyrhynchus, 

 in which all the species are adorned "with the most brilliant 

 metallic colours, banded and spotted in a curious manner, 

 and are very smooth and hard. Other genera of Curculionidae 

 (Desmidophorus, Alcides), which are usually very differently 

 coloured, have species in the Philippines which mimic the 

 Pachyrhynchi ; and there are also several longicorn beetles 

 (Aprophata, Doliops, Acronia, and Agnia), which also mimic 

 them. Besides these, there are some longicorns and cetonias 

 which reproduce the same colours and markings ; and there 

 is even a cricket (Scepastus pachyrhynchoides), which has 

 taken on the form and peculiar coloration of these beetles 

 in order to escape from enemies, which then avoid them as 

 uneatable. 1 The figures on the opposite page exhibit several 

 other examples of these mimicking insects. 



Innumerable other cases of mimicry occur among tropical 

 insects ; but we must now pass on to consider a few of the 

 very remarkable, but much rarer instances, that are found 

 among the higher animals. 



Mimicry among the Vertebrata. 



Perhaps the most remarkable cases yet known are those of 

 certain harmless snakes which mimic poisonous species. The 

 genus Elaps, in tropical America, consists of poisonous snakes 

 which do not belong to the viper family (in which are included 

 the rattlesnakes and most of those which are poisonous), and 

 which do not possess the broad triangular head which charac- 

 terises the latter. They have a peculiar style of coloration, 

 consisting of alternate rings of red and black, or red, black, 

 and yellow, of different widths and grouped in various ways 

 in the different species ; and it is a style of coloration which 

 does not occur in any other group of snakes in the world. 

 But in the same regions are found three genera of harmless 

 snakes, belonging to other families, some few species of which 

 mimic the poisonous Elaps, often so exactly that it is with 

 difficulty one can be distinguished from the other. Thus 

 Elaps fulvius in Guatemala is imitated by the harmless Plio- 

 cerus equalis ; Elaps corallinus in Mexico is mimicked by the 



1 Covnpte- Rendu de la Societe Entomologique de Belgaue, series ii. ; No. 59, 

 1878. 



