STATES OF INSECTS. 315 



for an amour : since not only have those with long man- 

 dibles been often taken united with those that have short 

 ones a , but the same difference obtains in the sexes of 

 other species. This is particularly observable in Lucanus 

 Jemoratus, of which I received from Brazil many speci- 

 mens agreeing in every respect except in this, that one 

 had short and the other very long mandibles. These 

 organs vary in different specimens, as to the number of 

 their teeth and branches. They are singularly robust in 

 L. Alces h ; but in none more threatening than in L. Ele- 

 plias c , 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 Lucanus 

 nebulosus Kirby, they assume a contrary direction d ; as they 

 do likewise in Lamprima Latr. e In Lucanus Capreolus 

 the points close over each other f . In Lethrus F. 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 g . In Siagonium quadricorne Kirby h 

 the mandible is furnished at its base with an exterior 

 horn, which is probably a sexual distinction. The male 

 of Synagris cor?iuta, a kind of wasp, is still more conspi- 

 cuous in this respect ; for from the upper side of the base 

 of its straight slender mandibles proceed a pair of crooked, 

 decurved, tortuous, sharp horns, not only longer than 



a By Rosel, by a friend of De Geer's, and by M. Marechal. De 

 Geer iv. 331 — . Nouv. Did. d'Hist. Nat. xviii. 225. 



b Oliv. no. i. Lucanus, t. \\.f. 3. c Ibid. t. iii./. 7- 



d Linn. Trans, xii. 410. t. xxlf. 12. e Ibid. vi. 185. t. xx.f. 1. 



f Oliv. ubi sup?\ t. ii./. 4. 



f Regne Animal, iii. t. x'm.f. 3. 



h See Vol. I. Plate 1. Fig. 3. 



