THE CANADIAN ENTOMOLOGIST. 213 



THE COLEOPTERA OF CANADA. 



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



XII. The Hydrophilid^ of Ontario and Quebec (concluded). 

 This paper can scarcely be considered in any sense an original one, 

 since it consists almost entirely of tables published in greater detail by 

 Dr. Horn in his reviews of this portion of the Hydrophilidt«. By 

 removing the extra-limital forms, I have been able in some cases to 

 modify the synopses so as to make them a little easier to follow, and it 

 is hoped that they will prove of use to many students of the Canadian 

 fauna who may not see the more complete originals. With this prelude, 

 which will place the credit where it properly belongs, we may proceed. 



Philhydrus, Sol. 



With this genus commences a series of less convex and usually 

 shining black species, which are common along the edges of ponds and 

 creeks, rising to the surface, after the manner of the Helophori, when 

 the water is agitated. Some of them resemble each other very closely, 

 but may be thus distinguished : 

 A. Above paler, testaceous to pale piceous. 



b. Prosternum distinctly carinate (. 14-. i8 in.) . . . nebulosus, Say. 

 bb. Prosternum not carinate. 



c. Mesosternal lamina very feeble, the anterior edge without 



distinct angle (.14- 16 in.) ochraceus, Mels. 



cc. Mesosternal lamina prominent, with distinct angle. 



Thorax piceous on the disk (.16-22 \n.).Ifamiltoni, Horn. 

 Thorax entirely testaceous (.18-.24 in.).. . .diffusus, Lee. 



AA. Above black or piceous black, margin sometimes pale, 

 d. Transversely very convex ; larger species. 



Thorax and elytra with pale border (.26-28 in.). ciucfus, Say. 



No pale border present (.28-.32 in.) consors, Lee. 



dd. Sub-depressed; smaller species {.16-.22 w.) . .perj>/ext(s, Lee. 



Helochares, Muls. 



Contains H. maculicoUis, Muls.: .16-22 in. long; yellowish or 

 testaceous above, with a rather large piceous thoracic spot ; head 

 more or less piceous. Elytra with two series of coarse punctures on 

 each (situated on the fifth and ninth intervals), and with ten moderately 

 deep impressed striae. 



