Note 4 — INTRODUCTION.

Now Loch Carra, in Co. Mayo. The bottom of this lake consists of white marl, which gives the water an extraordinary light green appearance; hence it is called in old Irish documents Fionnloch Ceara, or the "white lake of Carra." The metrical Dinnsenchus, however, calmly ignoring this obvious physiological reason, evident to anyone who had ever examined the lake, gives a fantastic account of the white wings of angels, from which it says the water derived its name.