30 THE CANADIAN ENTOMOLOGIST. 



cc. Prothorax with antebasal impression, which is transverse, 

 usually feeble and not distinctly linfiited at each 



extremity Haltiai. 



bb. Anterior coxal cavities closed behind. 



e. Antennae ii-jointed, approximate at base. 



f. Posterior tibiae sinuate near the apex, the sinuation limited 

 above by a distinct tooth ; first two ventral segments 

 connate, but with distinct suture ; thorax without ante- 

 basal impression C/icetoaiema. 



fl". Posterior tibix- without either sinuation or tooth. 



g. Thorax with distinct antebasal transverse impression, 

 usually well limited at its ends. Elytra punctato-striate. 

 h. Elytra glabrous. 



Form more or less ovate ; antennae 



moderate Crepidodera. 



Form elongate, parallel ; antennae as long or longer 



than body Orthaltica. 



hh. Elytra with rows of setaj on interstices, giving a 

 pubescent appearance. Form short, ovate; antennae 



not elongate Epitrix. 



gg. Thorax without transverse antebasal impression, 

 i. Spur of hind tibia small and slender. 



Thorax with short, deep longitudinally impressed 

 line each side ; elytra puijctato - striate, paler at 



tip M ant lira. 



Thorax without impression, elytral punctuation 



confused Systena. 



ii. Spur of hind tibiae broad, emarginate at tip ... . Dibolia. 

 ee. Antennae lo-jointed, hind tibiae prolonged beyond the in- 

 sertion of the tarsus, which is placed rather on the outer 



side, above the apex Psylliodes. 



CEdionvchis, Latr. 



The species of this genus are of large or moderate size (for Halticini) 

 and are readily recognizable on account of the inflated or globose claw- 

 joint of the hind tarsi. Some of them are of bright colours and hand- 

 somely marked. The Canadian forms are thus separated by Dr. Horn : 



A. Antennae stouter, scarcely one-half the length of the body; species 

 larger and more convex, front of head oblique, elytra never ex- 

 planate at sides. 



