434 DR. F, LEUTHNER ON THE ODONTOLABINI. 
be distinguished by the comparatively larger head, the larger antenne, the much longer 
and narrower front tibia, and the comparatively longer hind tarsi. They are sexually 
well developed, and the chitinous parts of the male organs are nearly as large as in the 
largest males. 
The females are less variable, and the species are so similar to each other that they 
can only be distinguished by minute characters, and even then, in many cases, only 
when the exact locality is known. Without localities they are valueless for scientific 
purposes. The females are considerably smaller than the males; they are consequently 
of a more rounded-oval shape. The head and mandibles are short, the canthus is 
generally very broad, and the occiput is so much contracted that the eyes nearly touch 
the front margin of the prothorax. When the mandibles are closed the head appears 
almost triangular. ‘The spine on the cheeks, so conspicuous in the males, is entirely 
absent in the females. The upper side of the head is generally more coarsely punctured, 
and there is a rounded epistoma distinct from the labrum. The mandibles are short 
and strongly curved inwards. ‘There is a sharp tooth near the tip, and three (which 
are generally unequal) on the inner side. The mentum is generally coarsely shagreened. 
The prothorax is not broader than the elytra, and the sides are shaped as in the male. 
‘The front tibize are scarcely longer than the others, and are comparatively broad; the 
terminal fork is but slightly developed, and the outer side is spiny. The males and 
females agree in coloration, except in O. stevensi, in which the male is entirely black, 
and the female has bicolorous elytra. 
The species are distributed over India, China, and the Malay Archipelago. We 
have scarcely any information respecting their habits; but Mr. H. O. Forbes informs 
me that O. wollastoni, a species with bicolorous elytra, flies by day in Sumatra, and 
the Rey. S. J. Pettigrew has observed that O. burmeisteri likewise flies by day in 
‘Travancore. 
This genus has been divided by authors into several subgenera!. ‘Thomson, in his 
Catalogue (Ann. Soc. Ent. France (4) ii. pp. 394, 395), distinguishes between Odonto- 
labis and Anoplocnemus, and Parry and Westwood separate Calcodes, which I cannot 
accept for want of sufficient characters, unless I should proceed on the principle of 
treating every small subsection as a distinct subgenus. I have therefore arranged the 
species in natural groups, which I designate by the name of a representative species, a 
practice which has long been in use among lepidopterists. (Comp. Diagram of the 
Species, p. 410.) 
1 The more carefully we investigate the species of a genus the more difficult it becomes to define either its 
limits or its characters. This leads to its being divided into so-called subgenera, which frequently include 
only a single species. The number of subgenera consequently increases enormously in proportion to the 
increase in our knowledge of species, until the best dictionary is scarcely sufficient to provide them with new 
names. Hence we may perceive that a genus is nothing more than a term of conyenience the definition of 
which may be altered at pleasure to include new species as they are discovered. 
