142 TiMEHRI. 



creatures which are preyed upon by other forms, perhaps 

 none are as wonderful as, certainly none are more 

 remarkable than, the condition of the anterior pair of 

 wings in certain of the Locustidse, such as Pterochroza 

 and other closely allied forms. In many genera of 

 the family, the front wings are elongated and narrow 

 like the wings of the grasshoppers, and are not only 

 coloured green like the ordinary leaf of a plant, but are 

 furnished with a large subcentral vein like the midrib 

 of a leaf, with small veins springing therefrom. In 

 Pterochroza and the other special forms referred to, of 

 which a few different examples have lately been added 

 to the Museum coIle6lion, the leaf resemblance is carried 

 to a most perfe6l degree. In shape they are ovate ; and 

 generally, as in the common elm leaf, the one side is 

 somewhat wider than the other, according to the depth 

 of the curve of the central vein, which is thickened like 

 a midrib. From this, side veins pass off in all direflions, 

 branching and reticulating, exa6l!y as in the case of the 

 leaf of an ordinary dicotyledonous plant. The colour- 

 ing of the wings is even more remarkable, the tint 

 varying according to the species. In one, the shade 

 varies from reddish-brown or reddish-yellow to a dull 

 purple, and closely resembles the shades to be found on 

 the young leaves of many of the forest trees, and more 

 especially on the mora (Mora excelsa). In another, 

 the tint is of a deep green, which is said to fade away 

 gradually on continued exposure to light after the death 

 of the inse6l. In a third, it is of a very pale yellowish- 

 brown, much like the colouring on an old and fading leaf 

 about to fall from the plant ; while, in a fourth, it is a 

 dull, dead brown, like that of a sere and fallen leaf. 



