THE BANK-MARTINS. 
3 2 9 
towards the middle or end of April, and leaves again from 
September onwards; on rate occasions Martins have been ob- 
served in England in November and December. Like all of 
the family, the House-Martin is untiring on the wing in pursuit 
of the gnats and small fliison which it feeds. It is not only 
found in country districts, but even frequents towns and builds 
its clay nest under the sheltering eaves of many a suburban 
villa. Soon a r ter its arrival it may be seen flying down to a 
puddle in the road or a pond to get the mud with which it 
makes its nest. Sometimes the nests are placed against rocks, 
especially in those localities where there is no sheltering build- 
ing to be made use of. 
Nest. — Made of small nodules of mud, the nest being lined 
with dry grass and a few feathers. It is rather large, and has 
the aperture near the top, from which the parent birds and the 
young are often seen protruding their heads. 
Eggs. —From four to six in number, and glossy white. Axis, 
o'75-o - 85 inch ; diam., o - 55-o’6. 
THE BANK-MARTINS. GENUS CLIVICOLA. 
Clivicola, Forster, Syn. Cat. Brit. B., p. 58 (1817). 
Type, C, riparia (Linn.). 
These birds are distinguished from the House-Martins and 
the Chimney-Swallows by several characters. They have a 
square tail, without the elongated outer feather, which dis- 
tinguishes the genus Htrundo , and they lack the feathered toes 
which characterise the genus Chelidon. Curiously enough, 
however, this feathered element in the feet is not altogether 
absent in the genus Cotile , for at the back of the base of the 
tarsus there is a tiny tuft of feathers. 
There are nine different species of Cotile known to science, 
two Paleearctic, six Ethiopian, and one Indian. The species of 
Europe, C. riparia , is also a common North- American bird, win- 
tering in the Neotropical Region. 
THE SAND-MARTIN. CI.IVICOLA RIPARIA. 
Hirundo riparia, Linn, Syst. Nat., i., p. 344 (H 66 ); Macg., 
Br. B., iii., p. 595 (1840); Seeb., Br. B., ii., p. 184 
(1884). 
