522 INSECTA. 



females is terminated by a tubular and horny ovipositor. 

 These Insects produce a small sharp sound by the rubbing of 

 the pedicle of the base of their abdomen against the interior 

 of the parietes of the thorax. 



In the system of Linnaeus, these Insects form three genera, 

 Cerambyx, Leptura and Necydalis, which Geoffroy, Fabri- 

 cius, and other naturalists have endeavoured to regulate and 

 simplify by the transposition of species, or by establishing 

 other generic sections. If we consider the number of spe- 

 cies that have been discovered since the time of the Pliny of 

 the North, the insufficiency of the characters which designate 

 these genera, and the confusion which still exists in several of 

 them, it will be plain that a general and elaborate revision has 

 become necessary let us hope that the researches of Messrs 

 Lepeletier and Serville, who have paid particular attention to 

 this family, will remove these difficulties. 



We will in the first place divide the Longicornes into two 

 sections. 



In those of the first, the eyes are either strongly emargi- 

 nated or lunate, or elongated and narrow ; the head is plunged 

 into the thorax, as far as those organs, without being distin- 

 guished from it by an abrupt contraction of its diameter, form- 

 ing a kind of neck ; in several it is vertical. 



In some, the last joint of the palpi is sometimes almost in 

 the form of a cone or reversed triangle, and sometimes nearly 

 cylindrical and truncated at the extremity. The lobe termi- 

 nating the maxillae is straight, and not curved on the inner 

 one at its end. The. head usually projects or is simply in- 

 clined, and in those, where, by a very rare exception the 

 Dorcaceri it is vertical, its width is nearly equal to that of 

 the body, and the antennae are very remote at base and spin- 

 ous. The thorax, frequently unequal or square, is rarely 

 cylindrical. 



These Longicornes are subdivided into two principal sec- 

 tions or small tribes. 



1. The Prionii, characterized as follows : the labrum null 

 or very small and indistinct ; the mandibles stout, or even very 



