DR. F. LEUTHNER ON THE ODONTOLABINI. 419 
is at present known, the short, broad, and very spinose front tibiz, the hairy covering, 
and the remarkable striation of the elytra in alternate hairy and hairless lines (traces 
of which likewise occur in hairy specimens of 0. carinatus, var. cingalensis, fig. 13), 
prevent our hazarding any conjecture respecting its actual affinities. 
ul. Heterochthes. 
Although the males (Pl. LXXXIV. figs. 5-7 and 9-11) much resemble those of 
the genus Odontolabis in the development of the mandibles, the shape of the mandibles 
in the female (figs. 8, 12) is very different from that which occurs in either of the 
preceding genera, and stamps this as a completely isolated form. ‘The female is 
relatively larger than in Neolucanus or Odontolabis, as is seen by the comparatively 
broader head, the hinder portion of which is broader, and projects somewhat from the 
prothorax, which renders the head more quadrangular. 
The female mandibles exhibit a gap which separates the obtuse basal from the apical 
teeth. This is not altogether new, for the gap is present in the females of other 
Odontolabini; but the inner base of the mandibles is less strongly developed, and the 
flattened articulation is concealed by the semicircular epistoma. ‘The latter is almost 
entirely absent in the female of Heterochthes, and the result is that the basal part 
of the mandibles, which is generally protected, is much enlarged. The two species of 
Heterochthes exhibit very slight differences in the females, but in the males the differences 
are much more conspicuous. The male forms of H. brachypterus are insufficiently 
known, but do not appear to develop a central tooth producing a mesodont form as in 
H. andamanensis. ‘The two species are, as Professor Westwood has already pointed out, 
nearest allied to Neolucanus laticollis from Java, to which they bear, as higher-developed 
forms, the same relation as some of the species of Odontolabis to certain species of 
Neolucanus. 
PART II. 
DESCRIPTION OF THE GENERA AND SPECIES OF ODONTOLABINI. 
LUCANID&. 
Subdivision ODONTOLABINI. 
Odontolabide, Parry, Trans. Ent. Soe. Lond. 1870, p. 74. 
Clava of antennz triarticulate, the leaflets being flat, but considerably produced, 
extremely finely pubescent. Clypeus comparatively small. Eyes divided in both sexes 
by a canthus, which is remarkably broad in the female. Mandibles polymorphic, 
varying very considerably in size and shape. Anterior tibie in the males often con- 
siderably longer than the four hinder ones, very frequently curved, and their external 
armature very variable. The four posterior tibiz invariably unarmed in both sexes. 
3Q2 
