52 
THE ORDER OP COLEOPTERA. 
Second Sub-section, CLAVIOORNES. 
Antenme club-shaped. Subsist mostly upon decaying animal or vegetable substances. 
Tribe III. 
WATER SCAVENGER-BEETLES. 
Putrivora aquatica, Philhydrida,* MacLeay. 
I 
This tribe commences the series of beetles with clubbed antennae, a 
character which at once distinguishes the insects of this tribe from the 
predaceous water-beetles, with which they might otherwise be confounded 
on account of their aquatic habits and similarity of form. This tribe is 
composed of two very distinct sub-tribes. 
Sub-tribe 1. Macrodactyla, Latreille. Legs not fitted for swimming. 
Last joint of the tarsi very long, often as long as all the others united, 
and for this reason called Macrodactyla, which means long toed. Palpi 
of ordinary length. Antenna?, moderately clavate. Body clothed with 
silken hairs. Family, Parnidae. 
Sub-tribe 2. Paltpicornes, Latreille. Legs fitted for swimming (except 
the Sphaeridiidse). Palpi very long, usually longer than the antennas. 
Autenme strongly clavate. Body glabrous. 
These insects feed upon decomposing matter in water, and are one of 
the agencies which prevent water from becoming offensive in a state of 
nature. But some of them have been observed to be carnivorous in the 
larva state. 
The first sub-tribe are semi-aquatic, being found in mud, or adhering 
to stones under water by means of their stout claws. The second sub- 
tribe (except the Splueridihhe) are purely aquatic, but less rapid in their 
motions than the predaceous Water-beetles. Each of the sub-tribes is 
represented by one principal family, the Parnidae representing the first 
division and the Hydrophilidae the second. 
Family V. PARNIDrE. 
These are small sub-aquatic insects which have been sufficiently charac- 
terized above. The family is composed of three leading genera. Panins, 
Fab., having the antenme enlarged at base and at tip, and the hind coxa', 
dilated into a plate for the protection of the thighs; Plmis, Latr., with 
the antenme almost filiform, and the hind coxa? not dilated ; and Hete- 
rocerus, Fab., with the antenme much like Paruus, but the mouth organs 
are more strongly developed, and the anterior and middle tibia? are 
widened and armed with spines on the outer edge, by which they are 
enabled to burrow in the wet sand which they and their larva; inhabit. 
• 
, I‘ , i , oni the Greek philcv — to love ; mid hudor — water. 
