22 



THE CANADIAN ENTOMOLOGIST. 



A. Antennae geniculate. 



b. Elytra smooth or nearly so Lucanus. 



bb. Elytra striate and punctate (obsoletely in one case). 



c. Eyes strongly notched by the margin of the head. 

 Larger species Dorcus. 



cc. Eyes entire or nearly so Platycerus. 



AA Antennas straight (i. e., not geniculate). 



Smaller species. Front of head simply excavated or with a 



depression Ceruchus. 



Larger species. Front of head with a short bent horn, pointing 



forward Passalus. 



Further remarks on structural characters will be found under the 

 head of each genus. The specific differences indicated are in the main 

 those used by Mr. Fuchs in the paper above mentioned. Nicagns is 

 omitted, for though the genus is now included in the Lucanidfe, the single 

 Canadian species, N. obscurus, was treated of under the Scarab?eidje in 

 Can. Ent., Vol. XXVI., p. 206. It is entirely different in appearance 

 from the other Canadian Lucanids, looking, as Dr. Leconte has said, like 

 some of the Seric?e or a nearly smooth Trox. 



Lucanus, Linn. 

 Contains two Canadian species. They are large brownish beetles of 

 shining surface, with very prominent mandibles, which are most strongly 

 developed in the males. The tibiae are armed externally with large teeth, 

 but are without the finer serrations seen in the following genus. 

 Femora yellowish or very light brown. 

 Mandibles with but one tooth internally. 

 Head of well-developed male broader than 

 prothorax. .92-1.40 in. . . .datna, Thunb. 

 Femora dark brown or nearly black, not 

 lighter than the rest of the leg. Man- 

 dibles straighter, with several teeth in the 

 male, two ill-defined ones in the female. 

 Head narrower than prothorax. Punctu- 

 ation of upper surface of body better 

 defined than in the preceding .96-T.40 



in placidus. Say. 



Fig. 12 represents Z. damn. 



Fig. 12. 



