410 
INSECTA. 
COLYMBETES, ClaitV. 
All the tarsi composed of five very distinct joints ; but the four 
anterior, in the males, have the three first equally dilated, constitut- 
ing, collectively, a small palette forming a long square ; the antennae, 
at least the length of the head and thorax. The body is perfectly 
oval, and wider than it is high; the eyes are not protuberant, or but 
very slightly so * * 
H YGROBiA, Lat . — Hydrachna, Fab. Clairv . — Pcelobius, Schoenh. 
I'he tarsi also composed of five distinct joints, the four anterior of 
which are almost equally dilated at base, in the males, into a little 
palette forming a long square ; but the antennae are shorter than the 
head and thorax ; the body is ovoid and very thick in the middle ; eyes 
prominent f . 
H YDROPORus, Clairv . — Hyphydrus, Schoenh. 
The four anterior tarsi nearly similar, and spongy underneath, in 
both sexes, composed of but four distinct joints, the fifth being 
deficient or very small and concealed, as well as a part of the last, in 
a deep cleft in the third. 
These Insects have no apparent scutellum J ( h). 
aciculahis, Ib. Ill, 30 ; — D. leei-igatus, Ib. 23 ; — D. tripunctatus, Ib. 24 ; — D. ruficol- 
lis, Ib., II, 20 ; — D. vittatus, Ib., I, 5 ; — D. yriseus, Ib., II, 12 ; — D. sticticus, Ib., 
II, 11; — D. circumflexus, Fab. Of American species Vae D. fimbriolatus, verticalis, 
mediatus, taniolis, &c. 
* D. fuscits, Panz., Faun. Insect. Germ., LXXXVI, 5; — D. cinereus, Fab.; 
Panz., Ib., XXXI, 2 ; — D. zonatus, Fab. ; Panz., Ib., XXXVIII, 3 ; — D. bipuncta- 
tus, Fab. ; Panz., Ib., XCI, 6 ; — I), fenestrutm, Fab. ; Panz., Ib., XXXVIII, 16 ; 
D. chalconatus, Fab. ; Panz., Ib., 17 ; — D. ater, Fab. ; Panz. Ib., 15 ; — D. guttatus, 
Payk. ; Panz., Ib., XC, 1 ; — D. fidiginosus, Fab. ; Panz., Ib., XXXVIII, 14 ; — 
D. hipustulatvs, Fab. ; Panz., Ib., Cl, 2 ; — D. stagncdis, Fab. ; Panz., Ib., XCI, 
7 ; — D. transvei’salis, Fab. ; Panz., Ib., LXXXVI, 6 ; — D. abbreviatus, Fab. ; Panz., 
Ib., XIV, 1 ; — D. maculatv.s, Fab. ; Panz., Ib., 7 ; — D. agilis, Fab. ; Panz., Ib., 
XC, 2 ; — D. adspicrsus, Fab. ; Panz., Ib., XXXVIII, 18 ; — D. minutus, Fab. ; Panz., 
XXY'^I, 3, 5 ; — D. Leander, Oliv., Ib., Ill, 25; — D. varius, Oliv., Ib., II, 17 ; — 
D. himaculatus, Oliv., Ib., 18. See Clairv., Entom. Helvet. II, genus Colymbetes. 
Certain small species without any distinct scutellum, and in which the anterior 
tarsi of the males are but slightly dilated, compose the genus Lacophilus of Leach, 
who cites the following : — D. kyalinus, Marsh ; — D. interrupius, Panz. ? — D. minutus, 
L. ; — D. marmoreus, Oliv. See his Zool. Miscell. Ill, p. 72. 
p Hydrachna Hermanni, Fab. ; Lat. Geiier. Crust, et Insect., I, vi, 5 ; Clairv., 
Entom. Helv. II, xxvii. A, a ; — H. uliginosa, Clairv., Ib., B, b. 
These Insects with the Flalipli, in the system of Leach — Zool. Miscell. p. 68 — 
form a particidar group, the characters of which are : a scutellum ; all the legs 
adapted for walking, with five joints to all the tarsi and two terminal hooks to the 
last. 
The Hygrobia; have their exterior palpi somewhat enlarged at the end ; two stout 
and approximated spurs at the extremity of the tibiae, and their anterior tarsi sus- 
ceptible of being doubled under the tibiae to which they are annexed. 
X In the preceding divisions, some small species excepted, it is very apparent, 
(a) Add to the species of Colymbetes the C. erythropterus, fenestralis, arnbi- 
guics, seriatus, nitidus, bicarinatus, venustus, glyphicus, obtusatus, &c. Of the G, La- 
cophilus the L. 7nacidosus and in'oximus. — Eng. Ed. 
(b) Add of American species the Hydrop. undulatiis, oppositus, niger, catascopium, 
lacustris, parulklus, widViMns, &c, — E ng, Ed. 
