426 EXTERNAL ANATOMY OF INSECTS. 
never exceed. ‘They vary in length; though generally 
shorter than the maxillary palpi, yet in the ferocious 
tiger-beetles (Cicindela) they equal them in length; and 
in the hive-bee and humble-bee, and many other bees, 
they are considerably longer?. The two first joints of 
these palpi, however, in these bees are different in their 
structure from the two last, being compressed and flat, 
or concave; and the two last joints, instead of articula- 
ting with the apex of the second, emerge from it below 
the apex: so that these two first joints seem rather ele- 
vators of the palpi than really parts of them’. With 
respect to the relative proportions of their joints to each 
other: in some cases the first joint is the longest and 
thickest, the rest growing gradually shorter and smaller ¢; 
in others, the second is the longest‘; in others, again, 
the third‘, and sometimes the last‘; and often all are 
nearly of the same size and-length*. They are more 
commonly naked, but sometimes either generally or par- 
tially hairy. Thus in Cicindela, the last joint but one is 
usually planted with long snow-white bristles in a double 
series, while the rest of the joints have none; and in 
Copris all of them are extremely hairy. In shape they 
do not vary so much as the maxillary palpi, being most 
frequently filiform or subclavate, and sometimes seta- 
ceous; the last joint varies more in shape than the rest, 
and is often remarkably large, triangular, and shaped 
* Kirby Mon. Ap. Angi. i. t. xii. neut. f. 1. g. c. 
» Ibid. 93. 103—. t. vi. Apis * *. b. f. 3. b,c. 
® Bid, £. Bop epee. 0: ¢ Ibid. t. ix. Apis **, ¢. 2, yf. 3. 6. 
© Clairv. Ent. Helvet. ii. t. xxiv. f. 1. ¢. 
f Prare XXVI. Fic. 24, 28. b". 
& Mon. Ap. Angl. i. t. 1. Melitta **. b. fi 2. €. 
