NORTPI AMERICAN COLEOPTERA. 43 



SPARSUS Group. 



In this group the rostrum becomes quite stout and relatively short, 

 more or less distinctly angulated at the sides. Scape of antennae 

 impinging against the upper part of the eye ; supraorbital sulcus 

 always present. The thorax is very densely and finely punctate ; 

 has, however, with the scaly vestiture intact, a finely granular ap- 

 pearance. Legs at least moderately stout; tibiae not denticulate 

 within. Tarsi less slender, anterior of the male with the third joint 

 dilated, deeply bilobed. 



The species are closely related and diflicult to differentiate ; the 

 following table will assist the student in identifying them : 



Larger, alternate elytral iuterstices with a row of setse ; each elytron subacu- 

 minate at apex. 

 Somewhat broader and stouter, densely scaly, uuicolorous ; tarsi wider. 



sparsus. 

 More elongate; elytra ferruginous, ahuost glabrous ; tarsi narrower. 



longulus. 

 Smaller, each elytral interstice with a row of setse ; elytra not subacuminate at 

 apex. 

 Thorax strongly rounded at base and sides ; suborbicular, hind angles obsolete. 



rottiiiflicollis. 

 Thorax feebly rounded at the sides ; hind angles dLstinct, base subtruncate. 



Stouter, elytral setje very conspicuous obscurelliis. 



Slender, elytral set?e inconspicuous iiiibellis. 



I?I. sparsus Say — Elongate-elliptic; piceous, black ; above and underside 

 of prothorax rather densely covered with dirty gray or brownish scales, larger 

 and imbricate on the elytra, intermixed with stout, erect hairs on rostrum, head 

 and thorax. Antennne. tibipe and tarsi reddish. Eostrum stout, subangulated at 

 the sides; tricarinate, median carina .strongly prominent, lateral ones less so; 

 surface with fine longitudinal rugiB or striolate ; transverse sulcus very pro- 

 nounced ; scrohes short, ill defined f.osteriorly. Head convex, very short, trans- 

 verse, finely rugulo.se-punctate and like the beak, sparsely clothed with yellowish, 

 squamiform hairs. Thorax wider than long, scarcely narrower at apex than at 

 base ; sides broadly rounded, with a vague impression at the middle, apex feebly 

 constricted; transversely impressed in front and a median indistinct groove, 

 lobes feeble ; surface densely and finely piuictured, generally concealed by the 

 scales ; median vitta generally obsolete, lateral ones variable, flexuose. Elytra 

 about one-fourth wider than the thorax, slightly emarginate at base ; humeri 

 rounded, sides subparallel for two fifths their length, then gradually narrowed 

 and compressed toward the tip, each elytron distinctly acuminate ; .striae rather 

 fine, punctures large, subquadrate when denuded of this scaly covering, but 

 appearing small and remote, or completely concealed, with the vestiture intact; 

 interstices slightly convex, very finely punctulate, alternate ones ou the disc 

 with a row of setigerous punctures; setae long, slender, slightly clavate and 

 rather conspiuous ; alternate intervals more elevated ; sides and declivity mottled 



