DESMOPACHRIA.—BIDESSUS. 19 
This is the most minute species yet discovered of this genus. It is closely allied to 
the small and smooth variety of Hydroporus granum, Lec., found in South America ; 
but it is readily distinguished by the impunctate upper surface; with a strong lens, 
however, traces of obsolete punctuation may be seen on the wing-cases. 
8. Desmopachria mexicana. 
Latissima, brevis, nitida, sine pubescentia, crebre sat fortiter punctata, ferruginea, abdominis apice protho- 
raceque infuscatis, hoc transversim in medio dilutiore, antennis, pedibus elytrisque testaceis, his nigro 
signatis; clypeo acute marginato; prothorace utrinque plica curvata; coxis posterioribus sat fortiter 
punctatis. 
1 3; 
Long. 13, lat. ? lin. 
Hab. Mexico, Guanajuato (Dugés, coll. Sallé). 
This species is very similar to Hydroporus latissimus, Lec., but is entirely destitute 
of the lateral foveze of the wing-cases, and shows numerous other less important 
distinctions. It is also very similar to D. variegata and D. dispar, but is readily 
distinguished by the prothoracic impression and the punctate coxe. The head is 
almost impunctate; but the punctures on the thorax are numerous and distinct, 
although fine. The punctuation of the elytra is rather close, but not coarse, and is 
absent at the side margins. The punctures on the hind coxe are not dense, and, 
though quite distinct, are not very coarse. The dark marks on the wing-cases cover 
a large portion of their area in an irregular manner, leaving, however, the sides and 
apex pale ; in addition to the larger mark, there is a small isolated one on each side 
some distance behind the shoulder. The hind tarsi are infuscate. I do not know the 
sex of the unique individual described. 
BIDESSUS. 
Bidessus, Sharp, Trans. Roy. Dubl. Soc. n. s. U1. p. 852 (1882). 
Hydroporus (ex parte), Aubé, Spec. Gén. vi. p. 468. 
The small insects of which this genus consists are numerous in species, and are found 
in most of the warmer parts of the world. About 100 species are known at present. 
1. Bidessus discedens. 
Ovalis, postice acuminatus, subtus convexus, glaber, nitidulus, testaceo-ferrugineus ; elytris secundum suturam 
nigro signatis et fortiter punctatis, ad latera levigatis, basi in medio plica profunda, sat elongata ; 
capite in medio distincte marginato. 
Long. 13, lat. ? lin. 
Hab. Mexico. 
Head reddish yellow, very shining impunctate, distinctly margined in front in the 
middle. ‘Thorax yellowish, with a longitudinal infuscation on the middle, a very 
distinct plica at the base on each side of the middle; the surface shining, but little 
DD 2 
