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; /-///, thoracic 

 somites; a', rudimentary fore ^^•ing; a-, hind wing. 



Order VI. Coleoptera. 

 The beetles are the highest Hexapoda T^•ith biting mouth parts. They 

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

 and TOngs. The mandibles are strong; the ma.xilL-c (fig. 470) have 

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

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



FiG. 470. Fig. 471. Fig. 472. 



Fig. 470. — ila.xilla of Procrusles coriaceits. c, cardo; le, galea; li, lacinia; pnt, 

 palpus; st, stipes. 



Fig. 471. — Calosoma sycophanta (after Ludwig-Leunis). 

 Fig. 472. — a, pentamerous tarsus of Dytiscus; h, cr}-plopentamerous 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 pupa; libene, while the larvas (fig. 458) show many modifications 

 corresponding to the mode of life. Another character is afl'orded by the 



