434 DR. F. LEUTHXBR ON THE ODOXTOLABINI. 



be distinguished by the comparatively larger head, the larger antennse, the much longer 

 and narrower front tibise, 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 tliat the eyes nearly touch 

 the front margin of the prothorax. When the mandibles are closed the head appears 

 almost triangular. The sphie 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 tibia; 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 0. stevensi, in whicli tlie 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 0. woUasfoni, a species with bicolorous elytra, flies by day in Sumatra, and 

 the Rev. S. J. Pettigrew has observed that 0. burmcisteri likewise flies by day in 

 Travancore. 



This genus has been divided by authors into several subgenera i. Thomson, in iiis 

 Catalogue (Ann. Soc. Ent. France (4) ii. pp. 394, 395), distinguishes between Odonto- 

 labis and AnopJocnemus, and Pariy and Westwood separate Calcodes, which I cannot 

 accept for want of sufiicient characters, unless I shouUl 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 lepidoptcrists. (Comp. Diagram of the 

 Species, p. 410.) 



' 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 sul)gcnora consequently increases enormously in proportion to the 

 increase in our knowledge of species, until the best dictionary is scarcely sufiicient to provide them with new 

 names. Hence we may perceive that a genus is nothing more than a term of convenience the definition of 

 which may be altered at pleasure to include new species as they are discovered. 



