65 



16 (5, 15). Lateral vittae without branch, becoming indistinct 

 or obsolete in front of middle of thorax, median distinct; 

 elytral intervals sutequal, punctulate; size small (6.5 mm.). 

 Penn., Ga., 111., Oregon sayi. 



17 (4). Median vitta forked in front, branches curving outward ^ 



and often joining tip of laterals, lateral branch feebl.e or tj^/1' 

 wanting; elytral intervals alternating, the broader and more 

 convex biseriately, the others uniseriately punctate; size small 

 to medium (6-10 mm.). IT. S placidus. 



18 (3). Lateral vittse entirely absent. 



19 (20). Thorax broadest in front of middle, with very coarse 



variolate punctures sparsely and irregularly placed, sometimes 

 a short, narrow tubercle near middle, occasionally extending 

 posteriorly as an obsolete raised line; elytral surface uneven, 

 striae with very coarse variolate punctures forming irregular 

 transverse rows, intervals flat, uneven, especially the 6th and 

 7th, uniseriately and finely punctulate; entire surface usually 

 with uniform coating; size small (5-6 mm.). Urbana and 

 Springfield, 111 minimus.^ 



20 (19). Thorax broadest behind the middle, regularly rounded, 



uniformly, densely, and moderately coarsely punctate, sometimes 

 a fine smooth median line; elytra evenly rounded, stride with 

 coarse punctures, intervals flat, with a single row of less coarse 

 punctures; surface with argillaceous coating, the narrow spaces 

 between the thoracic punctures usually denuded; size small 

 (6-7 mm.). Penn., Ga., Fla., Ind., 111., Mo., . .pctrvulus. 



IMMATURE STAGES. 



The only species hitherto sufficiently described in its immature 

 stages is robushis,— a species so infrequent in Illinois that Eiley's 

 elaborate description (46-141) need not be here repeated. 



*Sphenophor7/» minimus, n. sp. Surface opaque l)]ack, covered with uniform pale ochreous or 

 cinereous coating, except tiie rostrum In front of the int^ertion of the antennae, the anterior surface 

 of the fore femora at base, the Icnees, the tips of the tibiae, some of the sternal sutures, a spot at the 

 middle of the abdomen on the second, or first a.id second, ventral segments, and the antennal club, 

 'which are shining black, the latter spongy pubescent at tip as usual; and the tarsi andfunicle of an- 

 tennae, which are shining brown. 



Ro.qtiura two thirds as long as thorax, moderately stont, slightly compressed, curved, tip not 

 dilated, base punctulate, broadly canaliculate, sub-carinate each side »f the sulcus, suddenly and 

 strongly dilated over the scrobes. 



Thorax longer than wide, nearly as wide as the elytra, broadest in front of middle, widening back 

 of the ai)ical constriction, at first very rapidly, then more slowly, to a point in front of middle; from 

 this to base slightly narrowing, sides nearly straight, base oblique each side of middle; surface 

 sparsely, coarsely, and irregularly foveate-pnnctate, a very small oblong tubercle, usually de- 

 nuded and shining, iii front of middle, from which an obsolete smooth narrow median line some- 

 times extends posteriorly, but does not leach the base. Scutellum oblong, flat, usually coated. 



Elytra broadest behind the base, narrowing strongly to apex; strine fine, with coarse foveate 

 punctures depressing the surrounding space and forming irregular transverse rows, making the 

 surface very uneven, e3;;eciall.v on the sixth and seventh intervals; intervals flat, suhequal, finely 

 uniseriately ])unctulate, the third, in some specimens, slightly elevated; subapical callus elevated 

 into a distinct tubercle with the posterior outline nearly vertical. Pygidium punctate, with a mi- 

 nnie ferruginous tuft of hair at each po-terior angle. Beneath uniformly, not very densely, coarsely 

 punctate, less coarsely on prosterriuni; femora and tibia? strongly punctate. Length niin. De- 

 ^, scribe*! from six males and five f*>males, from floating driftwood, 'and log-, near water, at Urbana and 

 Springfield, 111. The elytral surface of this species recalls canosws. It is the smallest in our fauna. 



