166 COLEOPTERA. 



ing their indirect mode of development, this order is 

 in many respects nearer to the Orthoptera and Hem- 

 iptera than to Hymenoptera or Lepidoptera. This is 

 shown primarily in the retention in many groups of a 

 Thysanuriform larva, and secondarily in the similar 

 retention of generalized characters in the aspect of 

 the adults. 



x^mong the orders I.-IX., the May-flies, dragon-flies, 

 stone-flies, and termites do not present any marked 

 tendency to the production of wing-covers in the first 

 pair of wings, but in the large and representative 

 orders, the Orthoptera, and Hemiptera (Heteroptera), 

 and in Dermaptera there is a decided tendency in this 

 direction, shown in the general thickening or partly 

 thickened character of the first pair of wings, and 

 their differences of color and use. There is also in 

 the same orders a marked tendency to differentiate 

 the prothorax, and this is frequently very large. 

 The Coleoptera carry similar tendencies to their 

 highest possible development ; the first pair of 

 wings are transmuted into true wing-covers, are 

 distinct in color, comparatively useless as organs 

 of flight, and entirely coriaceous. The abdomen is 

 like that of the more generalized orders, sessile or 

 continuous with the thorax, no true waist being devel- 

 oped, and the prothorax assumes great prominence. 



In most families, such as the Coccinellidie (lady- 

 birds), Carabidae (ground-beetles), Dytiscidae (water- 

 beetles), Silphidae (burying- beetles), Staphylinidae 

 (rove-beetles), etc., the larvae have more or less of a 

 flattened, active Thysanuran form and proportions, 

 and are, on account of their biting mouth parts, even 



