20 



The Tibia. T th part of the leg. It c- a sin- 



gle v icr than 'he femur, although it 



burrow in the -round. 



: less like a hand. 



insects one- or more spines 



:hcr hair- iiicli arm the le 



: tibial spurs, and are much used in classification. 



be fifth and in- ;>art of the leg. that 



> of a aeries of segments, varying 



in numbt -t common number of segments in the 



. Somel 



18 may appear to bear 



four li vary much in form, and thus present charac- 



;ul in classification. Sexual characters are also frequently 

 art. 

 rentral Surface Of the Segments of the tarsus in many insects are 



or of membrane, capable of inflation, or concave p., 



which act so as to prod, mm and thus enable the insect to walk on the 



i rush ions or plates are called pnli'illi (f 2 ). In 



:iie pulvillus of the distal segment of the tarsus is a circular pad 



In most descriptive- works this is referred 



though the other pulvilli are well developed. The pul- 



villi a: '.'ir//// by some writers. 



. many insects (g.g. most Diptera) the distal segment of the tarsus bears 



r of pulvilli, one beneath each claw. In such cases there is frequently 



pulvilli a third single appendage of similar structure; this is 



In other insects the empodium is bristle-like or alto- 



The pp>.\imal segment of the tarsus is designated in some descriptive works 

 <us. 



The normal number of wings is two pairs; but in 

 to the rder Diptera, there an- many insects which 



pair; and many other insects are \vin-!< 

 the first pair of win rticulated to tin- n, 



and the- x-coml pair, to tin- mctathorax. \Vlu-n but a single- 

 it i\ almost invariably tin: first pair. 



te-likc or membra: which is first developed 



dy-wall.* In the con; formation of 



:itral walls of this me united throughout 



tent. Tli-- ' - along which 



tiiirkriiings i,f the dorsal and ventral 



and ' ramework of the wing. 



termed th- ! the wings; and their 



is with ;m in om 

 "'sis. Sccdeso iidae. 



