243 . 
HYBROBXUS CHALCONOTUS. 
Order Coleoptera. Fam. Hydrophilidse Leach , Lat . 
Type of the Genus Dytiscus fuscipes Linn. 
Hydrobius Leach., Sam . — Hydrophilus Lat., Fab., Marsh., Gyll. , 
Germ . — Dytiscus Linn. 
Antennce inserted before the eyes at the base of the mandibles, 
not so long as the head, 9-jointed, basal joint long, curved, sub- 
clavate, 2nd much shorter elongate-ovate, 3rd slender and short, 
but longer than the 4th and 5th which are transverse, 6th con- 
siderably broader, somewhat boat-shaped, forming a cup to re- 
ceive the perfoliated and pubescent club, the 2 first joints of 
which are transverse kidney-shaped, the terminal one the largest 
subovate (6). 
Labrum transverse, punctured, with a line of deep impressions 
at the base, sides rounded, anterior edge slightly emarginate (1). 
Mandibles subtrigonate, bent and bifid at the apex y internal side 
densely ciliated with strong hairs (2). 
Maxillce rather long, terminated by an articulated lobe, ciliated 
with long bent bristles, a narrower lobe on the inside, ciliated also 
and having several short spines at the apex. Palpi long, naked, 
4-jointed, basal joint small, 2nd and 4th long, of equal length, 
the latter convex on the outside, rounded at the apex, 3rd 
shorter, narrowed at the base (3). 
Mentum large, transverse^oblong, slightly narrowed before, the 
* margin convex. Lip short and broad, narrowed at the base, an- 
terior margin producing long silky hairs, slightly concave, angles 
truncated, notched in the middle, with a small tooth. Palpi re- 
mote, slightly hairy, triarticulate, basal joint minute, 2nd long, 
broadest at the apex, 3rd shorter, external side convex (4). 
Oval or globose. Clypeus entire. Eyes simple, remote. Thorax sub- 
conic, truncated anteriorly. Postpectus simple. Scutellum distinct. 
Elytra rounded at the apex. Wings ample. Legs alike in both 
sexes. Tibise spurred, anterior producing short spines exiernally. 
Tarsi 5 -jointed, A first joints short, of equal size in the anterior pair , 
5th long. Claws simple (5, afore leg). 
Chalconotus Sam. Ent. Comp. p. 368. 
Piceous black, with a green and crimson cast (especially when 
alive), minutely, thickly and beautifully punctured j elytra with 
10 finely punctured striae on each, strongest towards the apex, 
the spaces between the 2nd and 3rd, 4th and 5th, 6th and 7th, 
and 8th and 9th, with an irregular row of stronger punctures 5 
beneath dull black 5 antennae, palpi, and legs castaneous, the 
club of the former fuscous, the thighs and tibiae very dark. 
In the Author's and other Cabinets. 
