194 



COLEOPTERA 



CHAP. 



two forms are very different they are liable to be mistaken for 

 distinct species. 



There are at present between 500 and 600 species of stag- 

 beetles known ; the Indo-Malayan and Austro-Malayan regions 

 being richest in them. Australia possesses many remarkable 

 and aberrant forms. In the Ceratognathini a group well re- 

 presented in New Zealand as well as 

 in Australia the structure of the 

 antennae is like that of the Scara- 

 baeidae, rather than of the Luca- 

 nidae. The most aberrant form 

 known is, however, our common 

 Sinodendron cylindricum ; this de- 

 parts in numerous features from 

 other Lucauidae, and instead of 

 the mandibles of the male being 

 FIG. w. Sinodendron cyiindricum. more largely developed, there is a 



A, Larva; B, pupa. New Forest. 



horn on the head ; it is very 



doubtful whether this Insect should be allowed to remain in 

 the family. Little is known of the habits and development of 

 Lucanidee, except in the case of three or four species that are 

 common in Europe. 



The common stag-beetle, Lucanus cervus, is our largest British 

 beetle. The larva much resembles that of Melolontlia mdgaris, 

 but attains a larger size, and the anal aperture is placed longitu- 

 dinally instead of transversely ; it lives in decaying wood, or eats 

 the roots of trees without being injurious ; its life in this state 

 lasts about four years ; the pupal, period is passed through rapidly, 

 and the perfect Insect may remain for months underground 

 before it becomes active ; this occurs in June and July. This 

 larva stridulates by scraping certain hard tubercular ridges on 

 the third pair of legs, over a specially adapted rough area at the 

 base of the second pair. 



The Passalidae and Lucanidae are united by some authorities 

 as a group called Pectinicornia ; the term Lamellicornia being 

 then confined to the Scarabaeidae. The Passalidae appear, how- 

 ever, to be really more nearly allied to the Scarabaeidae than to 

 the Lucanidae. 



Fam. 3. Scarabaeidae (Chafers'). The leaflets of the antennae 

 are well coadapted, and are susceptible of separation. The elytra 



