166 LUCANIDiE. 



'Yhv front lihiu is c-loscly serrate Uitenilly, the extremity is 

 liroad and ends in three jhort lobes. 



^. The surfaec is dull above and beneath, with the exception 

 of the mandibles and the hollowed anterior part of the head in 

 large specimens. Except njjon tliis ])art the head is densely 

 granular, tlie front angles are shai})ly produced and the eyes are 

 rather prominent. The head is produced behind the eyes and 

 the sides are feebly prominent there. The pronotum is very 

 minutely and densely granular, but less densely in the middle 

 than at tlie sides. The front angles are blunt, the sides scarcely 

 rounded to the lateral angles, which are very acute, and almost 

 straight fi-om there to the base. The elytra are dull except at 

 the sutural margin. The ttienturn is densely granular, opaque 

 aJid very feebly pimctured and the inetasternum and abdomen 

 are almost un2)uncturcd. The prosterual process is strong and 

 conical. The front tibia is minutely serrate, with small teeth 

 at intervals and the termmal fork is rather narrow. The middle 

 tibia has a minute lateral spine and the hind tibia has 

 none. 



Variation of the male. In the smallest male spechnens 

 (impress us Wat.) the head is short, the mandibles are about as 

 long as the head and serrate at the inner edge, the head is a 

 little hollowed anteriorly but not shining. In rather larger 

 examples a ])air of small tubercles become visible just behind 

 the hollowed area. At a further stage a longitudinal groove 

 appears between the tubercles, which now project forward 

 rather strongly. The front of the head becomes more deejjly 

 hollowed and very smooth and shining. As the mandibles 

 increase in length the fine serrations of the inner edge become 

 at first more mnnerous and afterwards, by the gradual dis- 

 appearance of those in the middle, become divided into two 

 series, a grou}) of about six small teeth close together at the base 

 and about four less ci-owded ones towai'ds tlie end. At a fin-ther 

 stage most of the small basal teeth also disa})pear, but the 

 course of development now differs in different regions. The 

 basal teeth generally become resolved into a pair standing side 

 by side and, in the Eastern Himalayas these two teeth persist 

 and, accompanying further increase in the size of the insect, 

 move ])rogressively farther apart, until in the largest specimens 

 the anterior one is a little in frc)nt of the middle of the mandible, 

 the other remaining at the base. This is the ])hase described 

 as a distinct s])ecies by Boileau and called poidtom. But the 

 basal teeth may resolve themselves into one only and this also, 

 with increasing size of the specimen, moves on towards the 

 other end of the mandible. This jihase was called by Gravely 

 the subspecies birmanicus, but it is not peculiar to Burma. 

 Burmese and Assamese males develoj) in this direction and full- 

 sized examples show the single tooth ])lace(l in the middle of tlu> 



