DR. F. LEUTHNER ON THE ODONTOLABINI. 419 



is at present known, the short, broad, and very spinose front tibiae, 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. carinafus, var. cingalensis, fig. 13), 

 prevent our hazarding any conjecture respecting its actual aiRnities. 



III. Ileterochthes. 



Although the males (PI. LXXXIV. figs. 5-7 and 9-11) much resemble those of 

 the genus Odontolahis 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 Hetcrochthes, and the result is that the basal part 

 of the mandibles, which is generally protected, is much enlarged. The two species of 

 Ileterochthes exhibit very slight differences in the females, but in the males the differences 

 are much more conspicuous. The male foims of //. hrachypterus are insufficiently 

 known, but do not appear to develop a central tooth producing a mesodont form as in 

 H. andamaiiensis. The two species are, as Pi'ofessor "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 Odontolahis to certain species of 

 Neolucanus. 



PART II. 



Descriptiox of the Genera and Species op Odontolabini. 

 LUCANID^. 



Subdivision ODONTOLABINI. 

 Odontolabidm, Parry, Trans. Ent. Soc. Lond. 1870, p. 74. 



Clava of antennae 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 tibiae in the males often con- 

 siderably longer than the four hinder ones, very frequently curved, and their external 

 armature very variable. The four posterior tibiae invariably unarmed in both sexes. 



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