322 



ORTHOPTERA 



species, although they are now referred by entomologists to 

 different trenera. 



Fig. 197. — Dolichoiioda palpata, male. Dalmatia. {After Brumier. 



The Locustidae display in the greatest possible perfection 

 that resemblance of the tegmina to leaves which we mentioned 

 when speaking of the general characters of the Orthoptera. The 

 wing-covers are very leaf-like in colour and appearance in many 

 Locustidae, but it is in the tribe Pseudophyllides and in the South 

 American genus Pterocliroza (Fig. 198) that the phenomenon is 

 most remarkable. The tegmina in the species of this genus 

 look exactly like leaves in certain stages of ripeness or decay. 

 In the tegmina of some of the species not only are the colours 

 of faded leaves exactly reproduced, but spots are present like 



those on leaves due to 

 cryptogamic growths. 

 Perhaps the most 

 remarkable feature 

 of these resemblances 

 is the one pointed 

 out by Brunner 

 von Wattenwyl,^ 

 viz. that the tracks 

 and spots formed on 

 leaves by the mining of 

 Insects in their tissues 

 are also represented in the leaf-like wing-covers of the Pterocliroza ; 

 transparent spots (a, a, Fig. 198) being present, just as they are 

 in many leaves that have been attacked by Insects. Brunner was 

 so much impressed by these facts that he came to the conclusion 

 that they cannot be accounted for on the grounds of mere utility, 



^ Verh. zool.-bot. Gcs. JFicn, xxxiii. 1883, p. 248. 



Fig. 1 



-Leaf-like tegmen of Pterochroza ocellata : 

 marks like those made by Insects ou leaves. 



