139 
irregularibus discoidalibus alteraque lateral! majore triangular! 
ante apicem fuscis, leviter tricostatis. Long. l!n. S • 
Head clothed with tawny pile. Antennae reddish_, bases of 
the joints pallid or ashy, apices dusky. Thorax much broader 
than the head, and much narrower than the elytra, convex and 
rounded on the sides, the broadest part being the middle ; sur- 
face olivaceous or tawny ashy, the middle occupied by a broad 
dusky vitta bordered by black lines ; there is also a dusky vitta 
on each side below the lateral dilatation. Elytra elongated 
and rather depressed; shoulders prominent, but obtuse ; apex 
obliquely sinuate-truncate, with both angles of the truncature 
produced (the external one most so), sides destitute of carinse; 
surface of each with three smooth costse, the innermost only 
strongly pronounced, covered with minute punctures, each bear- 
ing a short bristle ; dull greenish ashy, with small dark-brown 
specks and a larger triangular dark-brown spot on the sides 
near the apex. Body beneath obscure tawny ; middle of breast 
and abdomen, and terminal segment of the latter, blackish. 
Legs greenish tawny ; tibiae and tarsi ringed with black. Meso- 
sternum with a very large rounded tubercle. 
c? Terminal abdominal segment with both ventral and dorsal 
plates deeply notched. 
I met with a few examples only of this species in the dry 
woods near Santarem, at the mouth of the Tapajos. 
Genus Xylergates, nov. gen. 
Body oblong, robust. Antennae stout, moderately elongated, 
sparingly furnished with short bristles beneath. Thorax tuber- 
cular on the disk ; lateral tubercles large and placed near the 
middle of the sides. Elytra much broader than the thorax, 
their deflexed sides broad and vertical, but not separated from 
the dorsal surface by smooth keels ; surface costate and rough- 
ened by small tubercles surmounted by short bristles ; apices 
truncated. Sterna narrow. Terminal abdominal segment in 
the males with dorsal and ventral plates notched. Ovipositor 
of the females moderately elongated, conico-tubular ; dorsal 
plate obtuse, ventral truncated. Legs stout; thighs thickly 
clavate ; fore and middle tarsi dilated in the males; first joint of 
the hind tarsi about equal to the two following taken together. 
The robust forms and tubercular thoraces of the species com- 
posing this genus give them a strong general resemblance to 
the Acanthoderes ; they are distinguished, however, by the elon- 
gate gradually thickened basal joint of the antennae, the closure 
of the anterior acetabular sutures, the ovipositor of the females, 
and other characters. The genus is very closely related to 
p 2 
