314 STATES OF INSECTS. (Jmago.) 
organs vary in different specimens, as to the number of 
their teeth and branches. ‘They are singularly robust in 
L. Alces*; but in none more threatening than in L. Ele- 
phas», in which they curve outwards and downwards. 
In Mr. W. MacLeay’s genus Pholidotus, they are almost 
parallel to each other, and curve downwards; in Rys- 
sonotus nebulosus they assume a contrary direction * ; as 
they do likewise in Lamprima*. In Lucanus Capreolus 
the points close over each other®. In Lethrus in the 
female, but not the male, the mandible is armed below 
with a long incurved horn. In Lucanus serricornis 
they form a complete forceps‘. In the male Prionide 
(Prionus F.) the mandibles also are often as remarkable 
as in the Lucani, particularly in P. cervicornis and affini- 
ties. In Stagonium quadricorne § the mandible is furnish- 
ed at its base with an exterior horn, which is probably a 
sexual distinction. The male of Synagris cornuta, a kind 
ofwasp,is stillmore conspicuous in this respect; for from 
the upper side of the base of its straight slender mandi- 
bles proceed a pair of crooked, decurved, tortuous, sharp 
horns, not only longer than the mandible, but than the 
head itself®. Many sexual differences are observable in 
the mandibles of the various tribes of bees (Anthophila). 
Thus, in Colletes the male mandible is more distinctly 
bidentate at the apex than the female‘: in Sphecodes 
* Oliv. no. i. Lucanus, t. i. f. 3. > Ibid. t. iii. f. 7. 
© Linn, Trans. xii. 410. ¢. xxi. f. 12. 4 bid. vi. 185. t. xx. fi 1. 
© Oliv. wbi supr. t. i. f. 4. 
* Regne Animal. iii. t. xiii. f. 3. 
® See Vou. I. Prate I. Fic. 3. 
« Christ. Hymenopt. é. xviii. f. 2. 
i Mon. Ap. Angl. i. Melitta*.a.ti.f. 5. 9.7. 8. 
