THE CANADIAN ENTOMOLOGIST. 229 



THE COLEOPTERA OF CANADA. 



BY H. F. WICKHAM, IOWA CITY, IOWA. 



III. The Melolonthine Scarab^id/e of Ontario and Quebec. 



The members of this group are distinguished, as already stated, by 

 the position of the abdominal spiracles, which are placed in part on the 

 superior portion of the ventral segments, the rows feebly diverging ; the 

 last spiracle usually visible behind the elytra. Secondary sexual charac- 

 ters are displayed often in the antennse, the club being longer in the 

 males ; the legs and ventral segments also often give us a clue to the 

 sex of the specimen, as will be shown in the proper place. The following 

 partially artificial key will enable the genera to be properly identified so 

 far as the recorded species are concerned. 

 A. Middle and hind tibite with only one spur, which is sometimes obsolete. 



No onychium, body scaly Hoplia. 



AA. Middle and hind tibiae with two spurs, onychium well developed. 



b. Form elongate, slender ; colours metallic green or bronze (at 

 least in part) or yellow. 



Elytra not densely scaly ; claws chelate Diche/onycha. 



Elytra densely covered with ochreous scales ; claws not chelate 



Macrodactylus. 



bb. Form robust, heavy ; colour brownish, sometimes iridescent, 

 pubescent, or somewhat irrorated. 

 c. Ventral segments fiv^e. Elytra either uniformly rather finely 



punctured or with punctured striae Diplotaxis. 



cc. Ventral segments six. 



d. Elytra with rather indistinct but regular sulci or grooves 



on the disk. Size small Serica. 



dd. Elytra without striee or sulcations over the greater portion 

 of the disk. Size larger. 

 Antennae with the third joint not elongate, the club 



three-jointed Lachnosterna. 



Antennae with the third joint greatly elongate, the club 



three-jointed Polyphylla. 



In using the above table care must be taken to count «//of the ventral 

 segments — the first or last is in danger sometimes of being overlooked. 

 A reference to the specific characters, as given in the following synopsis, 

 however, will aid inexperienced workers in clearing up possible doubts. 



