118 ' THE CANADIAN ENTOMOLOGIST. 



The character mentioned above for the primary separation of the 

 groups of genera, the sculpture of the first dorsal segment, may need 

 some explanation. The rugosities referred to under group AA. are to 

 be seen near the first spiracle, and to be appreciated the elytron must be 

 raised. However, it will seldom be necessary to refer to this, if a little 

 experience, or a few named specimens, are in the possession of the 

 student, since the groups separate easily by their facies. 



Ilybius, Er. 



The following scheme gives, in tabular form, the difference between 



the Canadian species as defined by Dr. Sharp. Lacking two of them, I 



am unable to verify the characters : — 



A. Hind tarsi of males with the joints margined at the external lower edge. 



b. Last ventral of (^ not carinate, the apical portion with coarse 



longitudinal stria? (.46 in.) siibceneus, Er. 



bb. Last ventral of $ with distinct median apical carina. 



Outer claw of anterior tarsi emarginate near the base in the $ ; 



legs piceous (.45 in.) <f.-maculatus, Aube. 



Outer claw of anterior ^ tarsi simple ; legs rufous 



( 38 in ) angustior, Gyll. 



AA. Hind tarsi of $ not margined at the lower external edge ; last 



ventral with rather short carina, hind margin obscurely rugose ; 



anterior feet rufous, posterior piceous (.40 in.), .biguttalus, Germ. 



The considerable longitudinal convexity of the species of Ilybius, 



with their finely reticulate sculpture, renders them easily distinguishable 



from the neighbouring genera. In colour all are black above, more or 



less metallic, the elytra with two small pale lateral spots, one of which 



is sub-apical. /. viridiceneus, Cr., does not appear in the above table, 



since Dr. Sharp has placed it in synonymy with /. subceneiis, Er. 



CoPTOTOMUs, Say. 



C. interrogatus, Fabr., represents this genus. It is of ovate, sub- 

 convex form, about .28 in. long, head red with black vertex, thorax 

 reddish, black at base and apex. The elytra are brownish with pale 

 irrorations, a short vitta near the scutellum, and the external margin 

 irregularly yellow. The under side and legs are reddish. 



Ilybiosoma, Crotch. 



A black beetle about the length of the preceding is /. bi/arius, 

 Kirby. The thorax is short with rounded sides, rufescent in colour, and 

 with broad margin. The elytra are covered w'th little striolae, which, in 



