454 DR, F. LEUTHNER ON THE ODONTOLABINI. 
Measurements. 
Total length. Head. Mandibles. Prothorax, Elytra. 
millim. millim. millim. millim. millim, 
Sethe G4 13 by 22:5 15 11 by 23 28 by 27 
This interesting species, the unique specimen of which is an irregular mesodont 
form, is a native of Siam. Future observations alone can decide whether it is a dis 
coloured specimen of 0. sinensis, or whether the difference in the colour of the elytra is 
constant in Siam, as the somewhat differently formed mandibles might lead us to 
expect. 
14, ODONTOLABIS DELESSERTI, Guér. (Plate XCIL. figs. 1-3,¢; fig. 4,2.) 
2. Lucanus bicolor, var. delessertii, Guérin in Delessert, Souvenirs d’un Voyage dans 1’Inde, 
2¢ partie, p. 48, pl. xii. fig. 3 (a pretty figure; but not quite correct). 
Odontolabis cuvera, p., Parry, Trans. Ent. Soe. Lond. (3) i. p. 447. 
Male. Very like O. cuvera, but larger; body uniform black, except the elytra. 
Head quadrangular, with very prominent eyes, canthus narrow; the spine behind the 
eyes straight and well developed; mentum rectangular, thrice as broad as long; 
mandibles variable in size and shape; prothorax as in 0. cuvera; upper surface dull 
and rugose; prosternal process obtuse, and generally rounded off; elytra sulphur- 
yellow, with a triangular black mark, beginning at the shoulders, where it is broad, 
and gradually narrowing to the tip; rim of the elytra black beneath ; scutellum smooth, 
semicircular; front tibiee with from one to three spines above the terminal fork. 
Mandibles. 
1. Forma telodonta.—Similar to that of O. cwvera, but larger, and with two well- 
developed teeth at the base (figs. 1, 1 8). 
2. Forma mesodonta.—Head and prothorax dull, finely punctrued. Rim of the elytra 
black beneath (fig. 2). 
3. Forma priodonta.—Head and prothorax dull, finely punctured. Rim of the elytra 
black beneath. Front tibiae with two rows of fine punctures, and only two spines above 
the terminal fork (fig. 3). 
Female. Very similar to that of O. cuvera, with which it agrees in the colour of the 
body and elytra. Head more coarsely wrinkled, and the prothorax more convex; 
elytra broader and shorter, the black triangular spot extends at the base to the very 
shoulders, and narrows gradually towards the tip; the outer margin is black above, 
and often-widens somewhat at the tip; rim of the elytra black beneath; front tibize 
with three or four strongly developed spines above the terminal fork. 
Number of specimens examined: five males and four females, in the collections 
of Messrs. Parry, Moore, and Pettigrew. 
Habitat. Neilgherries, Malabar, and Travancore. 
