NORTH AMERICAN COLEOPTERA. 
269 
O. riifipeis Lee. — Elliptic, smaller and less robust than any of the preceding 
species. Black, thinly pubescent: antennae aud legs rufous: hind femora feebly 
incrassate, more or less piceous. Long. 2 mm. : .08 inch. 
Closely allied to the European 0. foliorum Miiller, from which it 
appears to differ by the prothorax being a little more transverse and 
not rounded in front. 
O. minutus Horn is a variety of the above with the legs entirely 
piceons. It occurs in California and Colorado. 
XA\TIIUS gen . nov. 
I have established this new genus upon two very small, testaceous 
and thinly pubescent species having the claws simple, divergent, aud 
the tibiae almost truncate at the tip, with the armature very small. 
Beak long, rather slender and nearly straight, a little widened to- 
wards the tip, not striate ; scrobes straight, attaining the eyes, which 
are convex. Antenme moderately stout, inserted two-fifths ( S ) or 
one-half ( 9 ) from the apex ; scape slender, impinging against the 
eye ; funicle 7-jointed, first joint stout, second and third nearly equal, 
outer joints transversely rounded ; club rather loosely articulate ; 
front sulcate. Prothorax wider than long, feebly narrowed in front 
and slightly constricted behind the anterior margin. Elytra a little 
wider at the base than the prothorax, striate and punctured ; me- 
sosternum moderately wide between the coxie, declivous in front : 
first and second ventral segments moderately long, third and fourth 
shorter, equal ; fifth not longer than the fourth in the male ; py- 
gidium freely exposed in both sexes. Legs moderately slender, 
thighs feebly clavate ; tibiae straight, slightly widened towards the 
tip ; anterior and middle with a very small, scarcely perceptible 
hook, posterior feebly mucronate at apex ; tarsi with the third joint 
broadly bilobed ; claws simple. 
The two species are amongst the smallest in the tribe and are 
distinguished as follows : 
Larger, rufo-testaceous ; prothorax more densely pimctured, ])ubescence con- 
spicuous 
Smaller, pale testaceous: jirotborax remotely punctured, pubescence very fine. 
lili|Mitamis. 
X. pygiiiiiPiis u. sp. Plate vii, figs. 37, 37«. — Elougate-subovate, nifo-testa- 
ceous, pubescence white and rather long, especially on the i>rothorax. Beak 
shilling, finely punctured. Head sparsely punctured and pubescent, frontal 
sulcus long. Prothorax moderately wider than long, feebly rounded on the 
sides in front; surface coarsely aud densely punctured, each puncture bearing a 
long hair. Elytra a little wider behind the middle: sides nearly straight for 
