262 COLEOPTERA 



CHAP. 



bark of trees and bushes, or in roots thereof; some inhabit the 

 stems of herbaceous plants and one or two of the smaller forms have 

 been discovered to live in the parenchyma of leaves. A few are said 

 to inhabit dead wood, and in Australia species of Mhon dwell in 

 galls on various plants. Buprestid larvae are of very remarkable 

 shape, the small head being almost entirely withdrawn into the 

 very broad thorax, while the abdomen is slender.^ A few, how- 

 ever, depait from this shape, and have the thoracic region but 

 little or not at all broader than the other parts. The larvae of 

 Julodis — a genus that inhabits desert or arid regions — are 

 covered with hair ; they have a great development of the 

 mandibles ; it is believed that they are of subterranean habits, 

 and that the mandibles are used for burrowing in the earth. 

 Only the newly hatched larva is, however, known. 



Series IV. Heteromera. 



Tarsi of the front and middle legs loith Jive, those of the hind 

 legs ivith four, joints. 



This series consists of some 14,000 or 15,000 species. 

 Twelve or more families are recognised in it, but the majority of 

 the species are placed in the one great family, Tenebrionidae. 

 The number of visible ventral segments is nearly always five. 

 Several of the families of the series are of doubtful validity ; 

 indeed beyond that of Tenebrionidae the taxonomy of this series 

 is scarcely more than a convention. The larvae may be con- 

 sidered as belonging to three classes ; one in which the body is 

 cylindrical and smooth and the integument harder than usual in 

 larvae ; a second in which it is softer, and frequently possesses 

 more or less distinct pseudopods, in addition to the six thoracic 

 legs ; and a third group in which hypermetamorphosis prevails, 

 the young larvae being the creatures long known as Triungulins, 

 and living temporarily on the bodies of other Insects, so that 

 they were formerly supposed to be parasites. 



^ It seems impossible to understand the morphology of the anterior segments by 

 mere inspection ; the anterior spiracle being seated on the segment behind the 

 broad thorax. Considerable difference of opinion has prevailed as to -what is head, 

 what thora.x ; the aid of embryology is necessary to settle the point. The larva 

 described by Westwood {Mod. Glassif. i. 1839, p. 229), and figured as probably 

 Hujjrcstis attenuata, is doubtless a Passalid. 



