On Aquatic Carnivorous Coleoptera or Dytiscide. 801 
either side is a distinct, longitudinal, somewhat oblique fovea, extending from the middle to the line of 
the base; the surface is thickly punctate ; when viewed obliquely, a transverse shallow depression may 
be discerned near the middle, and alsoa minute punctured fovea near to the anterior margin; in colour 
black, the anterior margin and sides being distinctly suffused with flavous; elytra broad, robust, very 
finely pubescent ; beneath this pubescence are distinct punctures, and also a faintly punctate stria; at 
the anterior margin, halfway between the suture and the lateral angles, is a short depressed fovea, corres- 
ponding in position with the fovea on the thorax; in colour a deep brown black ; abdomen and under- 
side black: legs rufous ; antenne rufo-fuscous.” 
This is a species of Bidessus.—D. 8. 
1397. Hydroporus masculinus, Crotch, Tr. Am. Ent. Soc. V, p. 74. North America. 
“Somewhat obovate, pointed behind, pale fulvous, breast and abdomen black ; head very finely punc- 
tulate ; thorax short, transverse, sides straight, base margined with black; finely and rather closely 
punctulate ; elytra thickly and finely punctulate, pale yellowish, with the suture and four narrow lines 
black (the first and third not quite reaching the base). fas, anterior claws much elongate, deformed, 
subequal, the external one flattened. L. 4:75 m.m.” 
“Lake Labache; very distinct by the male characters ; the third joint of the anterior tarsi is also 
feebly bilobed and the claw joint is large and hardly longer than broad.” 
This is a very distinct species of Ceelambus, and may be placed near Hydroporus nubilus (No. 403). 
—D. $8. 
1398. Hydroporus melancholichus, Motsch., Schrenck Reise, 1860, p. 100. (Hydroporus lugubris, 
Motsch., Bull. Mosc., 1845, IV, p. 353, pl. 6, f. 1). Kamtschatka. 
‘“Oblongo-ovatus, subdepressus, niger ; thorace transversim impresso ; hoc basi elytrisque dense 
punctatis, ultimis parce pilosis; antennarum basi, elytrorum margine reflecto pedibusque rufo-piccis. 
Long. 1# lign., larg. 1 lign.” 
“Tl ressemble un peu au H. planus, mais il est plus étroit. La téte est transversale avec deux 
impressiones arrondies entre les yeux, et une troisiéme moins profonde sur le front. Le corselet s’élargit 
vers les élytres et présente vers la base une impression ponctuée. Les élytres sont un peu plus larges 
que le corselet, en ovale allongé comme la base de ce dernier, la pubescence est peu épaisse ; la portion 
réfléchie des bords latéraux, la base des antennes et les pattes sont roussatres. Le dessous du corps est 
noir.” 
1399. Hydroporus mestus, Walk., List. Col. Lord., p. 10. Waddy Ferran. 
“ Black, elongate-oval, slightly shining. Head with a large reddish spot in the disc. Elytra smooth ; 
each with three testaceous spots at the base, with two indistinct streaks in the disc near the base, with 
a testaceous costal streak proceeding from the base and ending in a patch at nearly one-third of the 
length, with an elongated testaceous dot near the suture at half the length, with three posterior elongated 
testaceous dots, one near the suture, two subcostal and near a testaceous costal line; legs red. Length 
of the body 22 lines.” 
This name is in prior use for another species. I have not identified Walker’s description with any 
species known to me ; it is probably a Deronectes,—D. S. 
1400. Hydroporus monilicornis, Sahl., not. fenn., XIV, p. 154. Russian Lapland. 
“ Breviter ovatus, depressus, nitidus, niger, palpis, antennis, pedibus apiceque elytrorum ferrugineis , 
capite basi rufo-piceo; antennis medio incrassatis, articulis subglobosis; prothorace angulis posticis 
acutiusculis elytrisque parce subtilissime punctatis, subglabris. Long. 14 lin.” 
