372 Mr.H. W. Bates on the Longicorns of the Amazons. 
narrow and apparently entire, but showing, on close examina- 
tion, a very shallow emargination and minute tooth; disk regu- 
larly and rather deeply punctate-striate, black, a wedge-shaped 
basal spot and a broad median vitta fulvous. Body beneath 
black ; sterna and centre of the breast bright testaceous yellow. 
Legs black, base of thighs testaceous yellow. 
S. Paulo, Upper Amazons. 
2. Tyrinthia scissifrons, n. sp. 
T. elongata, linearis, setosa, fuliginoso-nigra; fronte, vitta laterali 
thoracis lineolaque laterali elytrorum fulvo-testaceis ; femoribus 
basi articuloque quinto antennarum rufo-testaceis ; antennis arti- 
culis tertio et quarto biciliatis ; fronte (maris) tumida, conica, apice 
fissa. Long. 4lin. ¢. 
Head testaceous yellow, vertex and occiput black ; upper part 
of the forehead (2%) conically produced and cleft at the apex, 
and antenniferous tubercles armed on the inner side with a 
conical prominence. Antenne as long as the body, black, with 
the fifth joint reddish; basal joimt on its upper side abruptly 
thickened, hairy ; third and fourth joints together longer than 
the whole of the remaining joints, slightly thickened and fur- 
nished beneath with two fringes of long and fine hairs. Thorax 
coarsely punctured, and with a smooth dorsal line, black, a 
narrow stripe on each side pale testaceous. Hlytra linear, singly 
rounded and entire at the apex; surface very closely punctured 
and furnished with three obtuse cost, dull black ; lateral edge 
and carina near the base dull testaceous. Body beneath dull 
black ; base of thighs reddish testaceous. 
Banks of the Tapajos and Ega, Upper Amazons. Mr. Fry 
informs me that the peculiar bilobed prominence of the head is 
found in the males of some Rio Janeiro species. ee 
frontalis of Guérin-Méneville (Ins. rec. par Osculati, n. 265) 
belongs to this genus. 
Genus IsoMERIDA, Noy. gen. 
This new genus is distinguished from Hemilophus by the an- 
tennal joints decreasing in length in regular proportion from the 
third joint to the apex, and by the fringe of hairs on their under 
surface existing in uniform density on all the joints. The only 
difference between Isomerida and Amphionycha les in the short- 
ness of the antennz, which are not longer than the body, even 
in the males, and decrease greatly in thickness from the third 
joint to the apex. 
I have adopted the name under which the genus stands in 
the collection of Mr, Alexander Fry. 
