8 THE LEGS. 



is to be regarded as composed of four segments,* a 

 \>iew which holds good likewise with the larvae, whose 

 fourth segment (which is never provided with legs like 

 the succeeding segments) ministers to the thorax 

 rather than to the abdomen, or the part of the body 

 subserving to nutrition. Latreille called it the " seg- 

 ment mediale," a term which is appropriate enough, 

 but probably it is best to call it the fourth thoracic or 

 body segment. 



The legs have two-jointed trochanters (PI. X, fig. 

 8, 1), and have on the apex of the tibiae (including 

 the front pair, a character which distinguishes them 

 from all other ffymenoptera) two spurs (calcaria) (PL 

 X, fig. 1, 24). The calcaria are absent in the 

 exotic genus Pacliylota. In length the legs are vari- 

 able, but they are never of excessive length or thick- 

 ness, nor is one part ever much developed in propor- 

 tion to the others. The spurs are sharp-pointed and 

 minutely-toothed with Dolerus, Cladius, &c. ; tubercle- 

 like with Cimbex and Lophyrus; while with many genera 

 (Emphytus, &c.) the point of the outer spine is dilated 

 at the end into a fleshy prong. The posterior calcaria, 

 are always simple and sharp-pointed, and one is longer 

 than the other. Hylotoma, Lyda, and Tarpa (among 

 European genera) bear one or more spines (PL X, fig. 

 1, 25) on the two hind tibia?, or one on all the 

 legs, as with Lyda pratensis, &c. Hylotoma has one 

 on each of the two posterior tibiae, Tarpa two on the 

 same parts ; some forms of Lyda have one on the 

 anterior and three on the two posterior. Pinicola, 

 again, has three on each of the two posterior tibiae. 

 The tarsi are five-jointed. The joints are unarmed 

 with Phyllotoma, but, with most of the other genera, 

 they are provided with leaf-like expansions on the 

 underside, called patella (PL X, fig. 6, 1). The 

 claws on the apex of the tibiae are either equally cleft 



* See Audouin, Ann. d. Sc. Nat., i, 1824 ; Latreille, Regne An. 

 v; Westwood, Int. ii, 92; Reinhard, B. E. Z., 1865; Palmen, Zur 

 Morphologic des Tracaeensystenas, 98. 



