THE LUCANID.E. 243 



some of the Indian species, in which they are some- 

 times three inches long. The Passalus tridens, also,, 

 from Java, is two inches and a half long. The ma- 

 jority, however, are of moderate or even small dimen- 

 sions. We have already said that the distinguishing 

 feature of the group is the great developement of their 

 mandibles, which are frequently angulated or toothed in 

 a remarkable manner: in the present family, this occurs 

 most conspicuously in Lucanus itself ; in which genus, 

 and in Dorcus, if they do not curve downwards, they 

 are horizontal ; but their most characteristic form, or 

 that which is most prevalent, is to curve upwards. 

 We also find their head frequently sculptured or tuber- 

 culated in a peculiar manner; but it is rarely that we 

 observe this feature occurring in the thorax: in the male 

 Sinodendron, however, it is particularly retuse. Very 

 few of the present family exhibit a metallic or coloured 

 clothing, but we still observe it in Platycerus. Their 

 natural history is very unvaried : we have above re- 

 corded their habits, which are possibly incidental to both 

 the typical families. Passalus and its affinities are said 

 to commit great devastation in sugar plantations in 

 South America and the West Indies. The larvae are 

 formed, as far as they are accurately known, upon the 

 usual lamelliform type. \~W. E. Sh.] 



(217.) The second group are all more or less dis- 

 tinguished for their metallic splendour, which is most 

 brilliant in Lamprima itself, and in Chiasognathus, a 

 superb insect both for size and colour, and in which the 

 mandibles of the tribe attain their greatest develope- 

 ment ; they are, however, slender, and, as well as in 

 Pholidotus, curve downwards: they have, beneath, a mo- 

 derately long horn at their base. There is less diver- 

 sity in the geographical distribution of the present 

 family, than in the preceding. Thus, Lamprima and 

 Rhyssonotus are confined to the Australian group, 

 where the former sometimes appear in excessive pro- 

 fusion, and seems to replace there the occurrence of Lu- 

 canus. Pholidotus is South American, where it has a 



