212 THE CANADIAN ENTOMOLOGIST. 
FAMILY HELOPIDÆ. 
Genus MERACANTHA Azrby.—Labrum transverse, scarcely emarginate ; 
labium subtriangular, longitudinally and obtusely ridged in the middle 
with a deep impression on each side ; mandibles bidentate ? at the apex ;. 
maxilla mutilated ; maxillary palpi first joint minute : second longer than 
the rest, clavate ; third obconical ; fourth very large, securiform ; labial _ 
palpi broken off; mentum trapazoidal; antennae filiform, scape incras- 
sated ; pedicel obconical ; third joint longer than the rest, subcylindrical, 
a little incrassated at the apex ; fourth shorter than the fifth, subobconical ; 
fifth longer than the subsequent ones, elongate, obconical; 6—r10 
obconical, gradually decreasing in length, and the oth and roth in thick- 
ness ; 11th ovate acute. 
Body ovate, convex, apterous. Head triangular; front elevated on 
each side at the eyes protecting the base of the antennae; eyes large, 
lateral, internally emarginate. Prothorax rather wider than long, narrowest 
anteriorly, subquadrangular ; margined on the sides and anteriorly, margin 
very slender. Scutellum an obtusangled triangle. Elytra with the 
epipleura narrow, falciform ; shoulders incrassated, armed with a tooth ;. 
calcaria very short and scarcely visible. 
[238.] 323. MERACANTHA CANADENSIS Æ%rby.—Length of body 6 
lines. Taken in Canada by Dr. Bigsby. 
Body black-bronzed, naked, glossy, punctured: on the upper side of 
the body the colour is more metallic. Head and prothorax confluently 
punctured, two last joints of the antennae pale from hairs ; elytra slightly 
furrowed, the sutural and the marginal furrows meeting at the apex and 
including the rest; furrows punctured ; interstices very minutely and 
thinly punctured ; sides of the abdomen longitudinally wrinkled: tooth 
of the shoulder short and wide, placed a little above the middle. 
FAMILY STENOCHIADÆ. 
Genus ARTHROMACRA Avrby.—Labrum transverse ; labium dilated 
above the insertion of the palpi, subemarginate: mandibles bidentate at 
the apex; maxillæ bilobed; lobes thick, obtuse; maxillary palpi 
incurved, four-jointed ; first joint minute; second longer than the rest, 
clavate; third shorter than the fourth, triangular; fourth very large 
securiform, with the truncature oblique: labial palpi three-jointed, last 
