OF SELBORNE. 
179 
Notwitlifiianding what has been advanced above, fome few fand- 
martins, I fee, haunt the fkirts of London, frequenting the dirty 
pools in Saint George's- Fields, and about IVbite-Chapel. The quef- 
tion is where thefe build, fince there are no banks or bold (hores in 
that neighbourhood : perhaps ihey neflle in the fcaffold holes of 
fome old or new deferted building. They dip and wafli as they 
fly fometimes, like the houfe-martin and fwallow. 
Sand-martins differ from their congeners in the diminutivenefs 
of their fize, and in their colour, which is what is ufually called a 
moufe-colour. Near Valencia, in Spain, they are taken, fays IVillughby^ 
and fold in the* markets for the table ; and are called by the 
country people, probably from their defultory jerking manner 
of flight, Papilion de Montagna, 
LETTER XXL 
TO THE SAME. 
DEAR SIR, Selborne, Sept. aS, 1774. 
As the fioift or black-martin is the largeft of the Britip hir undines, 
fo is it undoubtedly the lateft comer. For I remember but one 
inftance of it's appearing before the laft week in April: and in fome 
of our late frofty, harfii fprings, it has not been feen till the begin- 
ing May. This fpecies ufually arrives in pairs. 
A a 2 The 
