688 EXTERNAL ANATOMY OF INSECTS. 
most from this form; in the bees it is commonly much 
Jarger than the rest, especially in the last pair of legs, 
and nearly forming a parallelogram?; in Euglossa it is 
trapezoidal; in the majority nearly linear or filiform. 
With regard to their termination—in Brachycerus and 
some ants (Ponera, Myrmica, &c.,) the three first joints; 
in Dascillus, Lycus reticulatus and affinities, the third and 
fourth ; and in the great majority of the Tetramerous 
insects the penultimate joint is bilobed ; although in most 
Predaceous beetles this joint is intire or simply emargi- 
nate, yet in Colliuris it terminates in a single oblique 
lobe ; and in Lebia, Drypta, &c., it is nearly bipartite. I 
must now advert to the Ungula or claw-joint: it is usually 
clavate or thickest at the end and curved; bnt in the 
Asilide it is shaped like a vase or cup; in Phaneus, in 
the four posterior ¢arsz, in which the claws are obsolete, 
it is thickest at the base and sharpest at the extremity; 
it usually forms an angle with the rest of the tarsus, rising 
upwards, which enables the insect to move more easily 
without hindrance from the claws, and also more readily 
to lay hold of any object it meets with; but in the La- 
mellicorn beetles and many other insects it is in the same 
line with it. As in the beetles last mentioned this joint 
is often inserted in the extremity of the preceding one; 
but in G@demera it articulates with the middle of its up- 
per surface; and in Lycus and a numerous host of Te- 
tramerous beetles it springs from its base, just behind 
where it diverges into two lobes. 
I shall next call your attention to the different kinds 
* Mon. Ap. Angl. i. t. xii. neut. f. 20. 
> Pate XXVII. Fic. 44. s°. 
ls 
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