44 GEO, n. UORN, M. D. 



Easily known by its small size and smooth clypeus. The front is 

 acutely and rather deeply notched, the angles of the notch forming 

 obtusely rounded teeth, bounded exteriorly by a slight sinuation. The 

 prosternum in front has a rather long acute spine arising suddenly. 

 The vertex is usually tuberculate though often with a short, slender 

 horn. Length .32 — .44 inch ; 8 — 11 mm. 



Abundant from Canada to Florida and Texas, and to the base of the 

 Rocky Mountains. 



CANTHON, IIoflFm. 

 The present short review has been prepared in order to place be- 

 fore the American student the means of recognising our species, as 

 well as to enable certain of those least known to be recognised abroad. 

 la his admirable monograph of this genus, Harold has been unable to 

 place certain of our species in their systematic positions, as many of 

 the characters made use of by him have not been previously recog- 

 nized. In this monograph all our species known to him have been 

 correctly diagnosed. — (^Berlin Eiitom. Zeitschrift, 1868.) 



Our species may be arranged as follows: — 

 Hind tibiae with two spurs : 



Clypeus bidentate; body smooth, shining, deep blue indigaceus, Lee. 



Clypeus 6-dentate ; body sparsely granulate, opaque, black. ..nigricornis, Say. 

 Hind tibice with a single spur : 

 Himl femora coarsely punctured and setigerous : 



Thorax densely, not coarsely, granulate praticola, Lee. 



Thorax sparsely and coarsely punctured puncticollis, Lee. 



Hind femora smooth: 



Hind tibise distinctly arcuate, gradually broader to apex cyanellus, Lee. 



Hind tibise either straight or very feebly arcuate : 



Clypeus acutely 6-dentate; emargiuation between middle and hinder 

 tooth deep: 



Body nearly smooth probus, Germ. 



Body opaque and granulate: 



Finely and densely granulate; lateral strire of elytra 



deeper ebenus. Say. 



Coarsely and sparsely granulate; lateral strife of ely- 

 tra equal depressipennis, Leo. 



Clypeus 4-dentate, without lateral deep incisure : 



Humeral stria of elytra never carinate, often absent: 



Thorax coarsely, elytra less coarsely punctured, punctures squammu- 



ligerous, surface shining, eyes large perplexus, Lee. 



Thorax punctured or granulose, surface black opaque, not squammu- 



ligerous, eyes small simplex, Lee. 



Humeral stria distinctly carinate at base lecontei, Harold. 



Clypeus bidentate, hind tibise feebly arcuate (especially h\% ): 



Surface smooth or feebly punctured viridis, Beauv. 



