540 CLASS VIII. 
Dryops Oury., Parnus Fasr. Antenne frontal, very short, 
with ten or eleven joints, auriculate, with second joint large, cover- 
ing the rest. Mandibles not exsert. Maxille with two lacinie, 
the internal not broader than the external. T'arsi with five joints, 
the last joint and claws strong. Body pubescent and pilose. 
Helichus Ericuson, Dryops Leacu, Parygrus Ericus., Parnus 
Fapr., Ericus. 
Sp. Dryops auriculatus Outv., Latr., Parnus prolifericornis FABR., PANZER 
Deutschl. Ins. Heft 13, Tab. 1, Cuv. R. Ani., éd. ill., Ins. Pl. 37, fig. 5; 
23" long, black-brown, feet brown, covered with a silky glistering felt : 
this insect lives at the bottom of fresh water, amongst the roots of water- 
plants. 
Potamophilus GERMAR, Hydera LATR. 
Elmis Latr. Antenne mostly with eleven joints, filiform or 
scarcely incrassated towards the apex. Maxille with two horny 
lacinie, the external narrow, palpiform. Feet elongate, tarsi with 
five joints. 
Sub-genera: Limnius Mueut., Ericus., Stenelmis L¥on Durour, 
&e. 
Macronychus Murut, Larr, Antenne sexarticulate, with last 
joint oval, forming capitulum. 
Sp. Macron. quadrituberculatus, GERMAR Faun. Ins. Hur. X. Tab. 4, GUERIN 
Icon., Ins. Pl. 20, fig. 4. 
Georissus Larr. Antenne short, with nine joints, clavate, 
with club globose, triarticulate. Head nutant. Body globose, 
apterous. Elytra connate. Tarsi with four joints. 
Fig. PANzER Deutschl. Ins. Heft 62, Tab. 5, GeRMAR Faun. Ins. Eur. 
Fasc. 15, Tab. 3, Guerin Jcon., Ins. Pl. 20, fig. 5 &c. Small insects, 
scarcely 4” long, living on the banks of rivers and streams. 
Family LXI. Palpicornia. Antenne short, with six to nine 
joints, inserted in a deep sinus under the lateral margin of head, 
terminated by a club perfoliate or solid. Palps filiform, unequal, 
labial shorter, maxillary nearly of the length of antenne or some- 
times longer than antenne. Body gibbous, mostly hemispherical 
or oval. Mentum large, clypeiform. 
Spheridium Fasr. Maxillary palps nearly of the length of 
antenne, with four joints, the first small, the second incrassated, 
obeonical. Maxille with two lacinia membranous or coriaceous. 
