388 1NSECTA. 



The maxillary lobes, however, are membranous, or but slightly coriaceous, 

 whitish or yellowish; the external one is widened near the extremity, &c. 

 The posterior thighs are strongly inflated in a great many, and hence the 

 denomination of the family. 



All these insects have wings, and are found on the stems or leaves of various 

 plants, but, so far as regards a great number of species that inhabit France, on 

 those of the Liliacese particularly. The larva? of some the Donacia: attack 

 the internal part of the roots of aquatic plants, on which we find the perfect 

 insect. Those of several others live exposed, but they cover themselves with 

 matters with which they form a sort of case or scabbard, like that of the 

 Cassidse. 



We will divide this family into two tribes : 



The first, that of the SAGBIDES, is composed, as its name indicates, of the 

 genus 



SAORA. 



The mandibles terminate in a sharp point. The ligula is profoundly emar- 

 ginate or bilobate. The Sagrse properly so called, originally designated 

 by the name of Alurncc, are exclusively confined to certain parts of southern 

 Africa, Ceylon and China. Their palpi are terminated by an ovoid joint, 

 the divisions of the ligula are short, the thorax is cylindrical, the antenna; 

 are almost filiform, longer than the head and thorax, with their inferior 

 joints shorter than the others, and the four anterior tibise tolerably thick, 

 but slightly elongated, angular and straight. These insects have a uniform 

 but very brilliant colour, green, golden, or a fulgid-red, with a slight mixture 

 of violet. 



There are three subgenera, Megalopus, Orsodacna, Psammeecus. 



The second tribe, or that of the CRIOCERIDES, is distinguished from the 

 preceding by the mandibles, the extremity of which is truncated or pre- 

 sents two or three teeth, and by the h'gula, which is entire or but slightly 

 emarginated. 



It is composed of the genus 



CRIOCERIS, Geoffrey, 



Which is now divided into Donacia, HaEmonia, Petauristes, Crhcei-is proper, 

 &c. In some of these, the mandibles taper to a point, and present two or 

 three teeth at the extremity : the palpi are filiform. The antennaj of an ordi- 

 nary thickness, are almost granose in some, and in others composed of obco- 

 nical joints, thicker at their superior extremity. The Donacea are frequently 

 ornamented with brilliant bronzed or gilded colours. Several species are also 

 covered with an extremely fine and silky down ; they generally live on aquatic 

 plants. 



