V POLYMORPHA TROGOSITIDAE COLYDIIDAE 233 



injurious by eating the embryo of the corn, but it is ascertained 

 that it also devours certain other larvae that live on the corn. 

 This beetle has been carried about by commerce, and is now nearly 

 cosmopolitan. Our three British species of Trogositidae repre- 

 sent the three chief divisions of the family, viz. Nemosomides, 

 Temnochilides, Peltides ; they are very dissimilar in form, the 

 Peltides being oval, with retracted head. It is doubtful whether 

 the members of the latter group are carnivorous in any of their 

 stages ; it is more probable that they live on the fungi they 

 frequent. Peltidae stand as a distinct family in ma.ny works.^ 



Fam. 30. Colydiidae. — Antennae with a terminal club, tarsi 

 four -jointed, none of the joints Iroad ; front and middle coxae 

 small, globose, embedded ; hind coxae transverse, either contiguous or 

 separated ; five visible ventral segments, several of which have no 

 mvrement. This is a family of interest, owing to the great diver- 

 sity of form, to the extraordinaiy sculpture and clothing exhibited 

 by many of its members, and to the fact that most of its members 

 are attached to the primitive forests, and disappear entirely 

 when these are destroyed. We have fifteen species in Britain, 

 but about half of them are of the greatest rarity. There are 

 about 600 species known at present; jSTew Zealand has produced 

 the greatest variety of forms ; the forests 

 of Teneriffe are rich in the genus Tar- 

 phius. The sedentary lives of many of 

 these beetles are very remarkable ; the 

 creatures concealing themselves in the 

 crannies of fungus-covered wood, and 

 scarcely ever lea.ving their retreats, so 

 that it is the rarest circumstance to find 

 them at any distance from their homes. 

 Langelandia anophthalma, lives entirely 

 Fig. 114.— Ditoma crenata. Underground and is quite blind, the 

 Britain. A, Larva (after optic lobes being absBut. Some Coly- 



Perns) ; B, perfect Insect. ^ i 



diidae are more active, and enter the 

 burrows of wood-boring Insects to destroy the larvae {Colydiuvi). 

 Few of the larvae are known ; but all appear to have the body 

 terminated by peculiar hard corneous processes, as is the case 

 with a great variety of Coleopterous larvae that live in wood.^ 



■^ Catalogue of Trogositidae, by Leveille, in Ann. Soc. cnt. France, 1888, p. 429. 

 ^ For classification, see Sharp, Biol. Centr. Jmer. Col. ii. pt. i. 1894, p. 443. 



