484 



AETHROPODA. 



from these the order receives its name Coleoptera, sheath wings. 

 Tinder the elytra are protected the delicate much folded hinder 

 wings, the organs of flight (lacking in insects with fused elytra), 

 the second and third thoracic wings and those of the abdo- 



FIG. 514. FIG. 515. 



FIG. 514. Maxilla of Procrustes coriaceus. c, cardo ; le, galea ; IL lacinia vm nalrnis- 



st, stipes. 

 FIG. 515. Calosoma sycophanta. (After Ludwig-Leunis.) 



men are covered by the elytra, these are soft above. Externally 

 the relations of the elytra cause a regional division peculiar to the 

 beetles (fig. 515) : head, prothorax, and a third division composed 

 of meso- and metathorax plus abdomen covered by the elytra. 



The numerous species of beetles over 100,000 are described are sub- 

 divided into normal forms and Rhynchophora, the normal forms being 

 subdivided again upon characters derived from the tarsi as follows : 



Sub Order I. PENTAMERA. Tarsus five-jointed, the last club-shaped 

 and bearing the claws, while the other four are short and somewhat heart- 

 shaped (fig. 516, ). This is the largest division and 

 contains the tiger beetles (CICINDELID^E) and the pre- 

 daceous CARABIDJE (fig. 515) ; the water beetles, HYDRO- 

 PHILID.E and DYTISCIDJE ; the LAMELLICORNIA or SCARA- 

 BEID^, represented by the ' June bugs,' Melolontha* and 

 the large tropical Dynastes ; the fire flies, LAMPYRIDTE ; 

 the rove beetles, STAPHYLINIDJE, etc. 



Sub Order II. HETEROMERA. First and second 

 legs pentamerous, third apparently four-jointed ; few 

 forms belong here, among them the ' oil bottles ' (ME- 

 LOID.E) and the blister beetles, CANTHARID.E, both of 

 them containing a peculiar substance, cantharidin, 

 which renders the Spanish flies, Lytta vesicatoria, an 

 important ingedient of blistering plasters. Some of the 

 TENEBRIONID^E live in the larval stages in flour, etc. 



Sub Order III. TETRAMERA (Cryptopentamera). Tarsi with the 



FIG. 516. a, pen- 

 tamerous tarsus 

 of Dytisciis ; 6, 

 crypto pentamer- 

 ous tarsus of 

 Cocci n el la ; t, 

 tibia ; *, reduced 

 tarsal joint. 



