662 EXTERNAL ANATOMY OF INSECTS. 
connects the leg with the trunk of the insect. With re- 
gard to their shape, the most general form of the four 
anterior is more or less that of a truncated cone: in the 
Staphylinide, however, they tend to a pyramidal or four- 
sided figure ; as do the whole six in the Trichoptera : in 
numbers of the weevils and capricorns they are subglo- 
bose; in the Lamellicorns they are mostly oblong, and 
not prominent: the posterior pair in the Coleoptera are 
generally flat and placed in a transverse position, and 
more or less oblong and quadrangular: in Elater, &c., 
they are cuneiform: in Haliplus they are dilated, and 
cover the thigh? : in Buprestis, Copris, &c., they have a 
cavity that partly receives it: the corresponding part, 
the clavicle, in the arm of Gryllotalpa, is very large and 
remarkable; viewed underneath it is triangular, and 
trifid where the trochanter articulates with it: in that of 
Megachile Willughbiella the clavicle is armed with a 
spine». As to their proportions, the most general law 
seems to be, that the anterior pair shall be the shortest 
and smallest, and the posterior the longest and largest. 
In some instances, as in Buprestis, the two anterior pair 
are nearly equal; in others (Mantis, Eurhynchus), the 
anterior are the longest, in the former as long as the 
thigh, and the four posterior the shortest : in the Tricho- 
ptera, Lepidoptera, &c., all are nearly equal; in Mantis 
the two posterior, and in Phengodes the intermediate pair, 
are the largest; but in Necrophorus they are the small- 
est :—though almost universally without articulations, in 
Galeodes the clavicle consists of two and the coxaof three¢. 
‘Pare XV, Frei", r"' > Prate XXVII. Fic. 27. 
© L.. Dufour, Deser. des six Arachn. &c.: Annales Generales, &c. 
1820: 19. #. Ixix. f. 7. d. 
