546 INSECTA. 



preceding ones, and nearly forms a truncated ovoid, and where the 

 thorax is at least as long as it is wide(l). 



Psammcecus, Boudier. jinthicus, Fab. Latridius, Dej. 



Where the antennae, composed of short and crowded joints, gra- 

 dually enlarge, and where the maxillary palpi are abruptly termi- 

 nated by a stout triangular club. The thorax is wider than it is long. 

 The body is more depressed than in the preceding species, the an- 

 tennae are shorter and the eyes less prominent(2). 



The second tribe, or that of the Criocerides, is distin- 

 guished from the preceding by the mandibles, the extremity 

 of which is truncated or presents two or three teeth, and by 

 the ligula, which is entire or but slightly emarginated. 



It is composed of the genus 



Crioceris, Geoff. Chrysomela, Lin. 



Which we will divide as follows: 



Sometimes the mandibles taper to a point and present two or three 

 teeth at that extremity. The palpi are filiform. The antennae, of 

 an ordinary thickness, are almost granose in some, and in others are 

 mostly composed of obconical joints, or such as are evidently thicker 

 at their superior extremity. 



Donacia, Fab. Leptura, Lin. 



Where the posterior thighs are large and inflated; the antennae 

 are of equal thickness throughout and their joints are elongated; the 

 eyes are entire, and the last joint of the tarsi is enclosed for most of 

 its length between the lobes of the preceding one. 



These Insects are frequently ornamented with brilliant colours, 

 bronzed or gilded. Several are likewise covered with an extremely 

 fine and silky down, which may prove useful to them when they 

 happen to fall into water, as they live on aquatic plants such as the 

 Iris, Sagittaria, Nymphoea, See, to which they cling with great 

 tenacity. Their larvae live in the roots of the same plants. Their 

 chrysalides, according to the observations of M. A. Brongniart, are 

 attached to their filaments by one edge only, forming knots or bulbs. 



The anatomical researches of M. Leon Dufour have induced him to 



(1) See Lat., Gener. Crust, et Insect, III, p. 45, and I, xi, 5; Oliv., Col., Vi, 

 98, bis, and Gyll., Insect. Suec. Ill, 642- 



(2) Anthicus 2-punctatus, Fab.; I place this genus here with some hesitation. 



