TETEAMEROIJS PLANT-BEETLES. 163 



which I have found of much use in preparing the following tables of 

 genera. Mr. Crotch unites all the Phytophaga in the family of Ghry- 

 somelidcB, which he divides into ten sub-families, as follows : Donaciides, 

 Orsodacnides, Criocerides, Melolonthides, Cryptocephalides, Chrysome- 

 lides, Eumolpides, Galerucides, Hispides and Cassidides. 



The Orsodacnides do not seem to us to be sufficiently distinct from 

 the Criocerides, nor the Melolonthides (questionably so called) from the 

 Crytocephalides, nor the Eumolpides from the Chrysomelides, to be re- 

 tained as of equal rank. We will therefore divide the Chrysomelidte 

 into the seven following sub-families. The accompanying tables of the 

 minor groups exhibit a pretty full synopsis of N. American genera, ex- 

 cepting a few which are composed of but one or two rare species, usually 

 from the remote West : 



A. Body elongated ; thorax uot margined at tlie sides ; head slightly constricted be- 

 hind the eyes; eyes prominent; thighs usually more or less thickened. 

 B. Body much elongated;, first ventral segment very long; larvae live in the stems 



of plants Donaciides. 



B B. Body moderately elongated ; first ventral segment not much longer than the 

 others ; larvae live on the leaves of plants, sometimes cover themselves with 



excrement Criocerides. 



A A. Body more or less rounded (except Hispides) ; thorax almost always margined ; 



head not constricted ; eyes not prominent; thighs not swollen (except in 



Haltica and its sub-genera.) 



C. Antennas distant, being wider apart at base than the length of the first joint. 



D. Body oval ; abdomen wholly covered by elytra ; larvae live exposed on 



leaves Chrysomelides. 



D D. Bodj^ usuallj^ short and sub-cylindrical ; tip of abdomen vertical and 



uncovered; larvae live on leaves, in portable cases. Cryptocephalides. 



C C. Antennae approximate, being rarely wider apart than the length of the first 



joint. 



E. Antennae filiform and at least half as long as the body ; hind thighs, in 



one division, enlarged for jumping; larvae live on leaves or between 



their laminae Galerucides. 



E E. Antennae less than half as long as the body, and more or less thickened 

 towards the tip. 

 F. Head exposed ; form oblong and usually sub-quadrate ; surface usuallj"^ 

 strongly pitted or reticulated ; larvae live between the laminas of 



leaves Hispides. 



F F. Head concealed under the thorax ; form hemispherical ; surface 

 usually smooth; larvae live on leaves, covered by excrement: 



Cassidides. 



Sub-family DONACIIDES. 



This sub-family, composed mostly of the genus Donacia^ Fab., forms 

 a connecting link between the Lepturides of the preceding family and 

 the Criocerides of the present. Their form is considerably elongated, 

 and they can be distinguished with certainty by the unusual prolouga- 



