36 AN ACCOUNT OF BRITISH FLIES. 
2. Lyphlopsylla : 
8 combs along the back, octactenus, Kol. 
pas is » 5,  Aexactenus, Kol. 
Comb only on posterior margin of pronotum. 
4 genal spines, suscu/t. 
3 by assimilts. 
Three spines on the suture dividing ant. cavity from 
the front of head, gracilis. 
3. Hystrichopsylla : 
Cheeks and clypeus densely spinose, obdwsiceps. 
The geographical distribution of the “fleas” seems to be world- 
wide, occurring from the Arctic regions to the tropics. They seem, 
however, to flourish best in warm climates, where they swarm in 
every room. Darwin gives a curious episode respecting fleas on reach- 
ing the mountainous country nearCoquimbo. He says: “I enjoyed 
my night’s rest here from a reason which will not be fully appreciated 
_in England; namely, the absence of fleas! The rooms in Coquimbo 
swarm with them ; but they will not live here at the height of only 
three or four thousand feet.”* This, he states, cannot be on account 
of the trifling diminution of temperature at that height. They occur 
just as plentifully in the mountain chalets of Switzerland also as in 
the warmer valleys. 
There appear to be no records of fossil fleas, as far as I can make 
out. None seem to be recorded from fossil amber, as we might 
expect. 
Modes of Destruction : 
1. Careful sweeping of carpets, mats, and rugs upon which animals 
are in the habit of resting, and instantly burning the dust, 
thus stopping the development of the ova. If they are 
allowed to hatch, the small larvze soon migrate into cracks 
and crevices, and are then difficult to dislodge. 
2. Paraffin is found a good remedy for destroying the larvee as well 
as dispersing the adults, and should be applied fairly strong 
to all cracks and crevices where dust has accumulated. 
3. The leaves of the feverfew are also said to keep away fleas; 
whether this is true or not I am unable to say. 
4. The following method is taken from “Land and Water”: 
“Take a few handfuls of fresh garden mint, and strew them 
about the rooms, particularly under the beds. This plan I 
adopted when on the Neilgherry Hills with perfect success.” 
5. For cleansing floors, etc., a solution of carbolic acid or paraffin — 
* “Voyage of the Beagle,” Darwin, p. 344. 
