quentibus 2 longiore, 2° parvo, 3-11 subæqualibus. Thorax subcordatus, basi transversim truncatus leviterque prolongatus. Pedunculus brevis. Elytra apice fortiter subquadrate truncata, costata, costis 16 majoribus, in interstitiis subtilissime bicostulata, in sulcis (sulco e tribus inter costas binas majores medio excepto) tenuiter pilosa, in omnibus transversim regulosa. Pedes anteriores tibiis sat fortiter emarginatis, tarsis maris art. 1-3 leviter dilatatis, subtus squamularum seriebus 2 munitis, art. 1 elongato-trigono, 2-3 rotundato-trigonis, 3° præcedente parum minore, 4° parvo cordato 3° plus sesqui minore, his omnibus angulis acuminatis, 5° magno, unguibus simplicibus.
This diagnosis may appear somewhat vague, still I have been unable to express the characteristics of the insects from which it is drawn in more precise terms, although they have features quite peculiar to themselves by which they are easily recognised when once seen.
The points on which the three spec, which form this g. more or less disagree are the following: 1, the labrum: this is more transverse in H. elegans and less deeply emarginated in H. ruficollis than in the other two spec, respectively—still in all three it is emarginated and has moreover the peculiarity of being furnished with bristles at the two anterior corners: 2, the mentum: this is sub-quadratically emarginated, the lobes being strongly rounded on the outer side, and abruptly acuminated at the apex, at the base of the emargination it is furnished with a broad, excavated tooth which is inflected and obtuse at the apex—so far all three species agree—however, whilst in H. elegans and ruficollis this tooth is slightly emarginated, at the apex, it is sharply notched in H. bimaculata, in fact bilobed, the lobes being large and rounded at the apex. I look upon this notch, which is sharp but not deep, as a mere variation from the emargination existing at the apex of the tooth of the former two species. 3, the palpi: these, labial as well as maxillary ones, have their terminal joint truncated at the apex—and so far again all three species agree—however, whilst this joint is of elliptic form in the palpi of H. ruficollis, it is in H. elegans only so in the labial ones that of the maxillary ones being cylindric at the base.
