784 mr. m. jacoby on new [Dec. 16, 



Head with the usual transverse depression, light brown, deeply 

 punctate at the base, leaving, however, a space in the middle of the 

 vertex smooth ; anterior part testaceous ; maxillary palpi filiform ; 

 antennae reaching to about one third of the length of the elytra, the 

 first joint much thickened, as long as the third, the second short, 

 rounded, joints sixth to ninth thickened and widened, the rest a little 

 more elongate, closely pubescent. Thorax about twice as broad as 

 long ; the anterior angles pointed and slightly produced outwards ; 

 sides sinuate near the base, but not angulate ; surface with a shallow 

 depression on each side, and a short, raised, longitudinal, smooth 

 space in the middle, not touching either the anterior or posterior 

 margin ; the disk covered with punctures as deep as those of the 

 head, more curved near the base and sides than at the anterior 

 portion, and covered sparingly with golden-yellow hair ; an obscure 

 spot of fuscous is visible at each side and on the disk. Elytra much 

 wider than the thorax, convex and subcylindrical, finely punctate 

 striate, more obsolete near the apex, covered also sparingly with 

 silky yellow pubescence ; they are slightly depressed before the 

 middle, of a dark chestnut colour, rather shining, and have each an 

 obscure, round black spot placed in the hollow of the depression. 

 Underside and legs lighter- coloured, the posterior thigh with a 

 rather large black patch on the outside ; posterior tibiae near the 

 apex with comb-like teeth and one spur ; claws appendiculate. 



Hab. Amazons. 



The dilated antennae, antemedian depression of the elytra, together 

 with the spur at the posterior tibiae, show this species to belong to 

 Clark's genus Homammatus, although it might perhaps have been 

 placed, with equal right, amongst the genus Homotyphus or allied 

 genera. Von Harold, in the ' Coleopt. Hefte,' has already pointed, 

 out the artificial construction of many of Clark's genera, founded 

 very often on doubtful and variable structures of different organs ; 

 and it is very possible that the student may often be puzzled as to 

 the genus to which an insect of this family belongs. 



22. Allochroma bimaoulata, sp. nov. 



Oblong, ovate, robust. Light fulvous, glabrous ; antennas, the four 

 anterior legs, and a spot on each elytron before the middle black. 



Length 3 lines. 



Head with a few fine punctures, a round fovea in the middle of 

 the vertex, and a transverse groove between the eyes ; another deep 

 longitudinal fovea is situated between the antennae ; the latter are 

 short and robust, entirely black, the first joint is claviform, the 

 second short and rounded, the third nearly as long as the first, the 

 fourth and fifth joints shorter and of equal length, the sixth joint 

 dilated and much more robust than the others, the rest rather short 

 and slightly widened ; maxillary palpi robust, the penultimate joint 

 transverse, the last joint conical and pointed. Thorax transverse, 

 all the angles acute and rather produced, the sides distinctly angu- 

 lated before the middle, thence to the base concave, not straight ; 

 surface rather convex, with two shallow foveae at each side near 



