454 DE. F. LEUTIINER OJ^ THE ODONTOLABINI. 



Measurements. 



Total length. Head. Mandibles, 



millim. millim. millim. 



J 04 l;i by 22-5 1.5 



This interesting species, the unique specimen of wliich 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. Odo\tol.\bis delesserti, Guer. (Plate XCIl. figs. 1-3, cJ; fig. 4,2.) 



? . Lucanus bicolor, var. delessertii, Gueriu in Delessert, Souvenirs d'un Voyage dans I'lnde, 



2"= partic, p. J8, pi. xii. fig. 3 (a pretty figure; but not quite correct). 

 Or/ontolabis cuvero, p., Parry, Trans. Ent. Soc. Lend. (3) i. p. 447. 



Male. Very like 0. cuvera, but larger ; body uniform black, e.xcept 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 tibise with from one to three spines above the terminal fork. 



Mandibles. 



1. Forma teJoclonta. — Similar to that of 0. cuvera, but larger, and M'ith two well- 

 developed teeth at the base (figs. 1, 1 J). 



2. Forma mesodonta. — Head and prothorax dull, finely punctrued. Rim of the elytra 

 black beneath (fig. 2). 



3. Forma 2>riodoiita. — Head and prothorax dull, finely punctured. Rim of the elytra 

 black beneath. Front tibias with two rows of fine punctures, and only two spines above 

 the terminal fork (fig. 3). 



Female. Very similar to that of 0. 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 tibiffi 

 with three or four strongly developed spines abo\e 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. 



