NORTH AMERICAN COLEOPTERA. 39 



five forms united under tliis name in my cabinet. It is somewhat 

 difficult to decide upon characters which are specific and not sexual, 

 and since the antennae ditter so greatly with sex, we are comfielled 

 to throw out this organ, generally so valuable for purposes of classifi- 

 cation. If we examine attentively the males and females of a very 

 well-marked species, in which there can be no suspicion of mixture, 

 we find that the claws of the tarsi do not vaiy with sex, as can be 

 observed in ilicis (Knoch) ; also that, if we imagine a tangent line to 

 be drawn to the curve of the epistomal edge at the points where this 

 line meets the eyes, the degree of convergence of these tangent lines 

 is almost exactly constant for the same species, irrespective of sex; 

 other characters wliich are almost constant are the proportional 

 lengths of the palpular joints, the punctuation and sculpture of the 

 body, and the shape of the pygidium. With these premises we can 

 formulate the following differences for a few distinct species which 

 have been combined under the name indicated above. 



L.. auxia Lee. — This is distinct by reason of the peculiar formation of the 

 ejtistoma, the above-mentioned tangents being parallel ; the pygidinm is very 

 short in proportion to its width ; the sculptni e is coarse and rough ; the inner 

 tooth of the ungues is very long and strong, nearly equal to the remainder 

 of the claw. 



li. Drakei Kirb. — Body very robust, rather depressed : sculpture very 

 even, fine; general appearance smooth. The tangent lines of the clypeus 

 mutually make a very obtuse angle, and the epistoma anteriorly, instead of 

 being broadly sinuate, is notched in the form of an acute cusp, and is more 

 properly bilobed. This is a distinct species in facies. 



li. coiisiiuilis Lee. — The facies of this species is different from that of 

 fiisca, being much more elongate ; the sculpture is smoother and finer ; the 

 epistomal tangent lines make a very obtuse angle, meeting at a distance in 

 front of the elypeus scarcely greater than the length of the head. 



Li. fusca (Frtihl). — The sculpture is rough and uneven, more so than in 

 any other of this group, except anxia; the claws are also very diflerent from 

 those of the three preceding forms, the inner tooth being very small and the 

 remainder of the claw projecting very far beyond it, and with a less arcuate 

 curve ; the whole claw is also more slender. The epistomal tangents inter- 

 sect at a distance from the anterior margin about equal to the length of the 

 head and prothorax together. 



The series of specimens of these species which are before me are 

 scarcely large enough to enable me to define the species properly, but 

 enough has been mentioned to show that the various forms should not 

 be combined until a series can be formed, showing unmistakably a 

 gradual progression from one species to another, in all characters 



