I 



r 



THE CANADIAN ENTOMOLOGIST. 69 



ee. Antennae widely separated at base. 



Front coxae transverse, third tarsal joint usually 



ent're VIII. Chrysomelini. 



Front coxse rounded, third tarsal joint 



bilobed VII. Eumolphii. 



dd. Prothorax not margined at sides. 



f. First ventral about as long or somewhat shorter than 

 the two following. 



Claws simple, elytra punctato- 



striate III. Criocerini. 



Claws cleft or toothed, elytral punctures 



irregular II. Sagrini. 



ff. First ventral about as long as all the others 



united I. Donaciini. 



cc. Last dorsal abdominal segment exposed, declivous. Form 

 of body robust, compact, subcylindrical. 

 g. Surface of body coarsely tuberculate 



above V. Chlamydini. 



gg. Surface of body not tuberculate. 



Prosternum not separating front coxse ; antennie 



short and serrate IV. Clythrini. 



Prosternum extending between front coxae, antennae 



usually long and slender VI. Cryptocephalini. 



The Roman numerals before each tribal name show the order in 

 which they are taken up in the following pages. 



Tribe I. — Donaciini. 



Contains two genera, which are composed of very neat, graceful and 

 usually active species, found on or about such aquatic or subaquatic 

 plants as water-lilies, arrowheads (Sagittaria), pond-weed, and various 

 sedges. They have a habitus peculiarly their own, which if once ap- 

 preciated renders their future recognition easy at a glance. The head 

 and thorax are narrower than the elytra, which are attenuated toward the 

 tip — sometimes almost triangularly so. The antennae are rather long, 

 extending back beyond the base of the thorax ; the under surface of the 

 body is finely pubescent. In colour most of the species are metallic, 

 varying to blue or green, though a few are testaceous, at least in part. 



Elytra simple at tip Donacla. 



Elytra distinctly spinose at tip Hcemonia. 



