COLEOPTERA. 
467 
Drtops, Oliv . — Parnus. Fab. 
In Dryops proper, the antennse, shorter than the head, are received 
into a cavity situated under the eyes, and are almost covered by the 
second joint, which is large, dilated, ip the form of an almost triangu- 
lar palette, and projects in the manner of an auricle, whence the name 
of Dermeste a oreilles, given to the most common species by Geof- 
frey *. The palpi are not salient. 
2. Those in which the antennae, composed of eleven joints, are fili- 
form, or merely a very little thicker near the extremity, and at least 
nearly as long as the head and thorax. 
Elmis, Lat . — Limnius, Illig. 
They are found in water, under stones, or on the leaves of the 
Nymphaea f. 
3. Those in which the always very short antennae consist of but 
six or nine joints, and terminate in an almost solid, oval, or nearly 
globular club. 
Macronychus, Mull., Germ. 
These Insects have five distinct joints in the tarsi, an oblong body, 
and antennse of six segments, the last of Avhich — perhaps composed of 
three — forms an oval club ; they can be folded under the eyes J. 
Georissus, Lat., Gyll . — Pimelia, Fab.] 
Here the tarsi consist of but four joints ; the body is short, turgid 
and almost globular, and the abdomen embraced by the elytra ; the 
antennae are composed of nine joints and terminate in a round club 
formed by the three last §. 
FAMILY V. 
PALPICORNES. 
In our fifth family of pentamerous Coleoptera, as in the fourth, we 
observe antennae terminating in a club, usually perfoliaceous, but 
consisting of nine points at most in all, and inserted under the lateral 
and projecting edges of the head ; they are never much longer than 
the latter and the maxillary palpi, and frequently even shorter than 
the last-mentioned organs. The mentum is large and scutiform. 
The body is usually ovoid or hemispherical, convex or arched. 
The legs in several are adapted for natation, and then consist of but 
* Latr. Gen. Crust, et Insect., II, 55; Schoenh., Synon. Insect, I, ii, p. ii 6 
The Dryops Dumerilii presents some differences in the length of the legs, the form 
of the antennae and thorax, which have induced Doctor Leach to form a separate 
genus — Dryops — for it. The other species re-enter Parnus. 
t Latr., Ib., II, p. 49; Schoenh., Ib. I, ii, p. 117 ; Gyllenh., Insect. Suec. I, 
p. 551. 
J Macronychus quadrituberculafus, Miill. ; Illig., Mag., V; Lat., Gener. Crust, et 
Insect., II, p. 58 ; Parnus obscurus, Fab. ; Germ., Insect. Spec. Nov., I, p. 89. 
II Pimelia pygm^a, Fab., Georissus pygmceus, Gyll., Insect. Suec., I, iii, p. 675; 
Trox dubius, Panz., Faun. Insect. Germ. LXII, 5. 
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