Rev. H. Clark on the Halticide of South America. 393 
Oxygonus nigripenns. 
O. rufus, elytris pedibusque (femoribus basalibus exceptis) nigris: caput 
inter oculos oblique et ad frontem medium longitudinaliter fortiter 
foveolatum ita ut frons bituberculatus apparet: thorax antice et ad 
basin marginatus, impunctatus: scutellum rufum: elytra satis lata 
punctata nigra nitida, marginibus tenuiter rufis: corpus subtus rufo- 
ferrugineum : pedes nigri; femoribus basalibus flavis: antenne rufe. 
Long. corp. lin. 3, lat. lin. 13. 
The only species known to me, with the exception of O. violacez- 
pennis of this paper, the elytra of which are black and immaculate: 
from this latter species it may be readily separated by the deep and 
conspicuous longitudinally fovea on its head. 
Taken by Mr. Bates at Ega, Amazons. 
Oxygonus luridulus. 
O. oblongus, parallelus, punctatus, luride flavus : caput inter oculos trans- 
verse iterumque ad frontem longitudinaliter foveolatum, impunctatum : 
thorax impunctatus, flavus: scutellum fusco-flavum: elytra obsolete 
punctata, luride flava: antenne, pedes et corpus subtus flava. 
Long. corp. lin. 23, lat. lin. 13. 
I cannot but regard this as a distinct species ; it is closely allied 
to O. simplex, but differs in the medial frontal fovea, which is broad 
and short, and also in the distinctly more abrupt and prominent 
angles of the thorax. 
Brazil. A single specimen from the collection of the Marquis La 
Ferté. : 
Oxygonus simplex. 
O. parallelus, punctatus, pallide flavus: caput super antennarum basin 
oblique foveolatum, etiamque fovea ad medium brevis, profunda, longi- 
tudinalis: thorax angulis anticis et posticis vix ut in O. luridulo pro- 
minulis, impunctatus: scwtellum impunctatum : elytra leviter punctata ; 
corpus subtus, antenne et pedes pallide flavi. 
Long. corp. lin. 3, lat. lin. 13. 
Of an entirely pale flavous colour. To be separated from 0. luri- 
dulus by the obsolete angles of the thorax, and by the absence of any 
medial fovea of the head: it is very nearly allied to 0. acutangulus, 
Chevr., but is much smaller; the antenne, always black in that 
species, are here pale flavous, and the medial marking on the head 
is of quite a different form ; it is transverse and narrow, rather than 
short deep and broad as in that species. 
Santarem, Amazon. Taken by Mr. Bates. 
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