AMERICAN COLEOPTKRA. 99 



to me unconditionally by Mr. Schwarz, to whom I am indebted for 

 this privilege and, indeed, for more favors than I can well enume- 

 rate. 



Finally, to the Rev. Mr. Gorham of Southampton, England ; M. 

 Pic of Digoin, France; Mr. Edward Reitter of Paskau, Austria, 

 and to Messrs. Ganglbauer and Holdhaus of the Royal Museum of 

 Vienna, I am very grateful for the loan or gift of many of the 

 European species, as well as others from Central America and 

 Mexico, including in some cases even unique types. 



In drawing up the following descriptions the author has not at- 

 tempted to make them anatomically exhaustive, but merely to set 

 forth those characters which experience thus far shows to be most 

 useful for comparative study. It does not necessarily follow that 

 these characters will prove equally significant in a wider field, 

 though the personal examination of many European species, and all 

 but two of the recognized European genera, convinces the author 

 that with very few exceptions the scheme followed applies equally 

 well to the Nearartic and Palearctic faunas at least. 



PTIN1N.E. 

 Mentum triangular, usually acuminate in front and foveate or 

 impressed at base. Palpi short, labial 3-jointed, maxillary 4-jointed, 

 similar in form ; basal joint slender, curved ; second and third 

 shorter and stouter; terminal joint largest, oval, pointed. Labrum 

 transverse, truncate or feebly emarginate. Antenna?, inserted on 

 the front and more or less approximate at base, rather long and 

 moderately stout, filiform or feebly serrate, 11 jointed (9-jointed in 

 Pitnus), the joints not very variable in length. Eyes variable. Pro- 

 thorax small, without side margin, usually constricted behind, the 

 disk anteriorly frequently gibbous or tuberculate. Elytra much 

 wider than the prothorax, usually oval or globose, but more elon- 

 gate, with sides nearly parallel in one or both sexes of many spe- 

 cies of Ptinus. Prosternum very short, separating the prominent 

 coxse, the coxal cavities widely open behind. Mesosternum small, 

 subtriangular, the side pieces not reaching the coxa?, which are sub- 

 globose, only moderately prominent and distinctly separated. Meta- 

 sternum moderate or long, side pieces narrow ; hind coxa? more 

 widely, sometimes very widely separated. Abdomen with five ven- 



TRANS. AM. ENT. SOC. XXXI. MARCH, 1905. 



