x PHYLUM ARTHROPODA 24! 



there is a sucking proboscis developed from the labium, 

 enclosing the stylet-like mandibles and maxillae. In the 

 Diptera (House-flies, Gnats, &c.) the mandibles, usually not 

 developed in the males, are biting or piercing organs, while 

 the basal parts of the labium form a proboscis enclosing a 



Ibr 



mx, 



FIG. 132. Mouth parts of the Cockroach. Ibr. labrum ; md. mandible ; mxi. an- 

 terior pair of maxillae ; m. mentum ; me. and mi. outer and inner divisions of the 

 second pair of maxillae ; //. labial palp ; pm. maxillary palp ; st. stipes ; sm. 

 submentum. (From Lang's Comparative Anatomy, after Savigny.) 



sharp spine developed from a process on the roof of the 

 mouth. In the Lepidoptera (Butterflies and Moths), the 

 mandibles are aborted in the adult, and the maxillae are 

 developed into elongated half-tubes, which when applied 

 together, form a complete tube capable of being coiled up 

 Man. Zool. p 



