280 
COLEOPTERA. 
GrYRiNiDiE .—Whirligig Beetles. 
Antennce short, eyes divided, posterior coxce fixed , posterior legs formed 
into paddles. Larva aquatic , imago on surface of fresh water. 
There is little difficulty in recognising members of this family, small 
shiny beetles which move in incessant activity on the surface of streams 
and tanks. They are usually of a black 
colour, the submerged portion pubescent, 
the rest shiny. The head, prothorax and 
elytra are closely fitted, the antennae short 
and inconspicuous, inserted in a groove 
in front of the eyes : the head is well de¬ 
veloped with the large compound eyes divi¬ 
ded, so that one part is in the water, one 
part in the air. The fore legs are long and 
slender, the tarsi in the males of some spe- 
Fig. 157.— DineutEs 
cies dilated to form a plate which is set indicus. 
below with little suckers. The posterior 
legs are modified to serve as paddles, the femur and tibia each dilated 
into broad plates, the tarsal joints forming a single broad plate. The 
elytra may be wholly smooth or simply sculptured, or the ‘ ‘ submer¬ 
gence line ’ 5 extends along it, the part below being pubescent, as is the 
ventral surface of the body. A foetid liquid is excreted by these beetles, 
presumably as a protection. 
Nothing appears to be on record as regards the life-history of any 
Indian form ; elsewhere the known larvae are aquatic, living in fresh¬ 
water tanks and streams near or at the bottom; this larva has lateral 
processes on each abdominal segment, functioning as gills, as also four 
apical abdominal hooks and is active and predaceous on other aquatic 
