408 DR. F. LEUTHNER ON THE ODONTOLABINI. 
1. Neolucanus. 
Following Parry’s example, I have endeavoured to divide the species of each genus 
into small sections, according to their actual affinities, both on practical and theoretical 
grounds ; but I have slightly modified Parry's arrangement by commencing with species 
in which the males most resemble the females and ending with those in which the 
sexes are most dissimilar (comp. the preceding diagram, p. 407). 
The first section contains small species presenting very slight sexual differences, as 
is the case with J. laticollis (Pl. LX XXIV. fig. 14, fig. 39), and I therefore leave 
them unnoticed. The sexual differences are equally slight, both in the mandibles, the 
canthus of the eyes, the shape of the head and prothorax, and in the comparative 
length of the front tibie. 
Nothing can be said of the sexual differences of WV. lansbergit, N. muntjac, and N. 
cingulatus, as only one sex of each is known. The geographical distribution and great 
similarity of these species render it probable that they are all very closely allied. 
The second group may be more profitably studied. In the North-Indian N. casta- 
nopterus the mandibles are priodont in all the specimens examined by Parry, Bates, 
and myself; and the male (Pl. LX XXIV. fig. 13) and female (fig. 14) exhibit very 
slight differences in the head and canthus. But the most nearly allied species, WV. 
swinhott (Pl. LX XXIV. figs. 15, 156,169), from Formosa, is not only larger, but 
further differentiated ; as in all the largest telodont forms, the mandibles are forked at 
the tip. But the smaller specimens (fig. 15) retain the priodont form of their 
progenitors. In the female the slight difference from the male mandibles necessitates 
the remarkable widening of the canthus (for defensive purposes?) which gives the 
head such a peculiar triangular form. The slight variations in the shape of the 
prothorax and elytra are unimportant. The coloration of the whole insect and a slight 
but important morphological character—the hairiness of the mentum in the males—are 
quite constant. In J. castanopterus the chestnut-brown elytra are marked with a 
black transverse basal band (figs. 13, 14), which is nearly obsolete in WV. swinhoii. 
The allied species V. pallescens (Pl. LXXXV. fig. 2) and N. parryi (P). LXXXYV. 
fig. 4) illustrate this. In the former the elytra are dark brown, with only a trace of a 
narrow pale border, which runs from the tip to the middle, where it ceases. In the 
allied V. parryi there is a triangular mark in the middle of each elytron in both sexes. 
This coloration is repeated, somewhat modified, in the female of N. marginatus 
(Pl. LXXXYV. fig. 3), whereas the supposed male (fig. 1) is dark chestnut-brown. 
The differences of these species are very slight, apart from their constant local colour- 
variations. The hairy mentum in the males of these species is so characteristic that I 
rightly concluded, before the discovery of the male of WV. parryi, that it would also 
exhibit it. If fig. 1 is really the male of V. marginatus (which its analogy with 
Odontolabis stevensi renders probable), the gap between this species and NV. /ama (fig. 14) 
