72 ZOOLOGY 
Go 
are deposited amongst the dust in cracks or crevices; the 
small larvae have distinct head and jaws. 
Pulex irritans is the common flea. Sarcopsylla penetrans 1s 
the chigoe or jigger of South America; the female burrows 
into the foot of man or other mammals, and deposits her eggs 
there. If not removed the larvae hatch out and give rise 
to ulcers. 
Sub-order 2. Diptera genuina. 
Family CULICIDAE (gnats and mosquitoes)—_The members 
of this family are provided with very long and slender mouth 
parts. They are very widely distributed, extending from the 
arctic circle to the equator; the females lay their eggs on the 
surface of the water, on which they float in a boat-shaped mass. 
The larvae live at the bottom of ponds or swamps, eating 
decaying vegetable matter, and occasionally rising to the sur- 
face for air, which they take in through a special respiratory 
tube. The pupae are curiously curved and somewhat club-_ 
shaped; they swim actively about. The males do not leave 
the neighbourhood of the swamps where they are bred, but the 
females infest houses, etc. Culex pipiens is the common species 
of gnat in Britain. 
Fic. 209.—Tipula oleracea (the daddy- 
long-legs). 
Larva. 
bop 
Pupa case. 
Imago. 
co 
e 
Eggs, natural size. 
Family Trputmpaz (daddy-long-legs or crane-flies), — The 
familiar daddy-long-legs has long filiform antennae and very 
