HEXARTIIRTUS. 67 



Gciuis HEXARTHRIUS. 



Lucanus subg. Hexarthrius Hope & VVostw., Cut. Luc. Col. 1845, 



pp. 4, 30. 

 Cladognathus subg. Hexarthrius Bumi.. Ifnndb. Eiit. v, 1S47, p. 305. 



Typk, Lucanus rhitwceros Oliv. (Java). 



liaiiyc. The Indo- Malayan Rogi(jn. 



f!lul) of the aiiteima ooinposed of live; or six joints, usually 

 with the ])rowdiug joint also j)roduct'(l. Eyes inc-onijjletcly 

 divided. Middle and hind tibia^ eaeh with a strong lateral 

 spine in the female, the hind tibia of the male with only a 

 vestige or none. Tarsi long in the male, rather short in the 

 female. Clypeal pnx-ess divided from the front by a sutural 

 line. Maxillii^ witli a h(jrny hook to the inner lobe in the female. 

 Ligula composed of two slender, stnjngly divergent lol)es, the 

 labial palpi with the first and third joints long, the second 

 short. 



Tlie mandibles in well-develoi)ed males of Haxarthrliis arc 

 large. The si)ecies are of large size and closely related to 

 Durcas but with five or six joints instead of three in the club 

 of the antenna. The males of most of tlie species are, at least 

 in part, l)rown, red or yellow, whilst the known females are 

 black, but two of the Indian species are at present insufficiently 

 known and their females liave not l)ccn distinguished. 1 have 

 therefore had to omit them from my table of species. 



Key to the Species of Hexarthrius (males). 



1 (0) Head short, very broad in front, 



strongly contracted behind. 



2 (5) Tronotuni broadest before the 



middle. 



3 (4) Elytra each decorated with a large 



yellow patch jnuryi Hope, p. OS. 



4 (3) C'oloiir uniformly reddish brown . . Jorstcri Hope, p. O'J. 



5 (2) Pronotum broadest behind the 



middle innisuciti Thorns., p. 71. 



(1) flead longer, not very broa<l in front 



nor strongly contracted behind. 

 7 (10) Elytra very glossy. 



S (9) Lateral angle of the pronotum bhuxt ^f;(/vi/(;// I'arry, p. 72. 



i) (8) Lateral angle of the pronotimi sharp. flf/«/tcj/.s- Jord., p. 73. 



10 (7) Elytra dull davisoni Wat., p. 74. 



K( 11 to tlie Species (females). 



1 (4) Siiles of the pronotum coarsely and 



cl()st<ly punctured. 



2 (3) Lat<!ral angle of the pronotum very 



sharp parryi Hope, p. OS. 



3 (2) Lateral angle of the pronotum very 



blunt davisoni Wat., p. 74. 



4 (1) ISides of the pronotinn feebly punc- 



tured. 



r2 



