DR. F. LEUTHNER ON THE ODONTOLABINI. 411 
and from the gradual modification of the male mandibles in the species 1, 2, 3, on 
the one side, and in Q. gracilis (a), O. dalmani (8), and O. celebensis (c) on the other. 
In the former species the females are so similar in form that, although I have examined 
hundreds of specimens, I am hardly able to determine them with certainty unless the 
exact locality is recorded. In the females of 0. gracilis and 0. dalmani the prothorax 
is almost trispinose, as in the males. ‘The strongly developed pro- and mesosternal 
processes and the shape of the mandibles render it probable that these species are 
offshoots of 0. bellicosus. It will always remain uncertain whether they should be 
regarded as constant local races of 0. bellicosus, or as distinct species. In the Chinese 
dwarf form, 0. platynotus (Pl. LXX XVIII. figs. 9-12), the prothorax is similar in 
form in both sexes. In the larger males of 0. siva a front angle is developed; but in 
the males of the other species the prothorax is always distinctly trispinose. 
If we compare the forms of the mandibles of the males with each other we obtain 
the following results :— 
In O. platynotus, O. siva, O. gracilis, O. dalmani, and 0. celebensis, the two basal teeth 
are persistent, even in the terminal forms. In 0. Jellicosus (Pl. LXX XVIII. fig. 2) 
we find three basal teeth, but in the largest specimens the first projects more inwards, 
and the others disappear, so that the terminal form leads towards a mesodont form. In 
O. alces this development proceeds further, and a fourth form makes its appearance in 
which all the basal and central teeth disappear, and only the apical teeth remain. 
priod. | amph. mesod, telodont. | Number of spines. 
MMO PION MOCSE «(els atteiaieits teletelat | F=—————"| I arionce || “obese 
2p (Ob EGE os casos TABOO CONSE -———_———F | .::-:::: | Ce 
SP ONoraciiets ters Neate aes [eS A eae cial amen. 7} 
LE OS GIANT, oc pobooonrtoonovca|| cboacn ee (ie ee CC 
yee. 2-8 
BOL GTS soannoesasesa50c -_—_—_——“]_.- | .«---:- 
GO) MUAH so s5cnepencooo0C «|! .-_ | .«.:--:: 
Uo OGRE cog acco 1d j5pa Da OONe |\—__—__] .+.. O-1-2 
This differentiation of the mandibles is correlated with the diminution of the spines 
of the front tibie, which seems to confirm the above phylogenetic origin of the species 
(comp. p. 391, § 7). 
In the smallest priodont forms of 0. alces (PL LXXXIX. fig. 7) the front angles of 
the prothorax disappear, and only the middle spine projects. ‘The analogy of this form 
leads me to regard 0. camelus (Pl. XCVI. figs. 7, 8) as nearest related to the present 
group, although it is certainly an abnormal form. 
3P2 
