IV. INSECTA: HEXAPODA, COLEOPTERA 



423 



there. The quickly flying male (2) escapes from the pupal skin; it recalls 

 somewhat a beetle; has rudimentary fore wings and large hinder ones. The 

 wingless, legless female (i) remains in the pupal skin and is fertilized there; she 

 is viviparous. Insects infested with these parasites are 'stylopized.' The 

 affinities of the order are doubtful; they are frequently included with the beetles. 

 Slylops,* Xenos.* 



FIG. 469. Xenos rossi (after Boas), i, female; 2, male; 3, larva; I-1II, thoracic 

 somites; a 1 , rudimentary fore wing; a'-, hind wing. 



Order VI. Coleoptera. 



The beetles are the highest Hexapoda with biting mouth parts. They 

 are closest to the Orthoptera, as is shown by the structure of mouth parts 

 and wings. The mandibles are strong; the maxillae (fig. 470) have 

 lacinia and galea; the labium consists of a submentum (often called 

 men turn), behind which the rudimentary mentum with its palpi, para- 



FIG. 470. FIG. 471. FIG. 47 _\ 



FIG. 470. Maxilla of Procrustes coriaceus. c, cardo: le, galea; li, lacinia; pm, 

 palpus; st, stipes. 



FIG. 4ji.Calosonia sycophanta (after Lud \vig-Leunis). 



FIG. 472. a, pentamerous tarsus of Dytiscus; b, cryptopentamerous tarsus of 

 Coccinella; t, tibia; *, reduced tarsal joint. 



glossa?, and glossae (the latter frequently fused) are retracted. The group 

 is distinguished from the Orthoptera by the holometabolous development 

 with pupae liberae, while the larvae (fig. 458) show many modifications 

 corresponding to the mode of life. Another character is afforded by the 



