442 1NSECTA. 



We will divide this section into four great faniilies(l), the 

 two first of which are somewhat analogous to the first penta- 

 merous Coleoptera, in an excrementitious apparatus discovered 

 in several of their genera by the same savant; their chylific 

 ventricle also is frequently covered with papilke. In several 

 of these Insects, we find the vestiges of another secreting 

 apparatus but seldom observed among Coleoptera, that which 

 is denominated the salivary apparatus. The iiepatic vessels, 

 as in the Pentamera, with but few exceptions, are six in num- 

 ber, and have two insertions distant from each other : u at one 

 extremity," says M. Dufour, " they are inserted by six in- 

 sulated ends round the collar, which terminates the chylific 

 ventricle ; the other opens into the origin of the caecum by 

 trunks, varying in number according to the family and genus." 

 In some, where the elytra are generally solid and hard, and 

 the hooks of the tarsi are almost always simple, the head is 

 ovoid or oval, susceptible of being received posteriorly into 

 the thorax, or sometimes narrowed behind, but not abruptly, 

 and without a neck at its base. Many of these Heteromera 

 avoid the light. This division will comprise the three fol- 

 lowing families. 



FAMILY I. 



MELASOMA. 



This family consists of unmixed black or cinereous coloured 

 Insects, (from which is derived the name of the division,) 

 mostly apterous, and frequently with soldered elytra. Their 

 antennse, entirely or partly granose, almost of equal thickness 

 throughout or slightly inflated at the extremity, and the third 

 joint wholly elongated, are inserted under the projecting edges 

 of the head. The mandibles are bifid or emarginated at the 

 extremity; the inner side of their maxillce is furnished with a 



(1) In a natural order, the fourth is connected with the first by the Helopii 

 which Linnasus places in his genus Tenebrio. It is also evident that the Tenebrios 

 lead to Phaleria, Diaperis, &c, or to our second family. 



