COLEOPTERA . 
543 
at the roots of trees and grass; a few live under the bark of 
trees. 
The family GEORYSSID^ (Ge-o-rys'si-dae) includes only 
two American species. “ They are small, rounded, convex, 
roughly sculptured, black insects, found at the ijiargin of 
streams, on wet sand ; they cover themselves with a mass of 
mud, so that no part of the insect is visible.” (LeConte and 
Horn.) 
The family PARNID^E (Par'ni-dae) includes small water 
beetles, in which the legs are not fitted for swimming. The 
tarsi are five-jointed ; the first four segments of the tarsi are 
short and equal; the fifth is longer than the others con¬ 
joined ; the tarsal claws are unusually large. The body is 
clothed with fine, silken hairs, which retain a film of air when 
the insect is beneath the water. These beetles are found 
adhering to stones or plants beneath the surface of the water. 
The larva of Psephenus lecontei (Pse-phe'nus le-con'te-i) is 
common in the East, clinging to the lower surface of stones 
in rapid streams; and we have found it in muck near a 
spring. It is very flat and circular in outline 
(Fig. 652), and measures about five sixteenths 
of an inch in length. It is rarely recognized 
as an insect by the young collector. Other 
larvae of this family have similar habits, and 
resemble this species in form except that the 
margin of the body is notched between the 
segments. 
The family HETEROCERID^E (Het-e-ro- 
cer'i-dae) includes only the genus Heteroccrus (Het-e-roc'e- 
rus). These beetles “ are oblong or subelongate, oval, 
densely clothed with short silky pubescence, very finely 
punctate, and of a brown color, with the elytra usually vari¬ 
egated with undulated bands or spots of a yellow color. 
They live in galleries which they excavate in sand or mud 
at the margin of bodies of water, and, when disturbed, run 
from their galleries and take flight.” (LeConte and Horn.) 
Fig. 652. 
