'A long time after these things a servant girl went with the farmer's herd of cattle to graze them at the side of a loch, and she sat herself down near the bank. There, in a little while, what should she see walking towards her but a man, who asked her to fasg his hair [Welsh lleua]. She said she was willing enough to do him that service, and so he laid his head on her knee, and she began to array his locks, as Neapolitan damsels also do by their swains. But soon she got a great fright, for growing amongst the man's hair, she found a great quantity of liobhagach an locha, a certain slimy green weed [22] that abounds in such lochs, fresh, salt, and brackish. The girl knew that if she screamed there was an end of her, so she kept her terror to herself, and worked away till the man fell asleep as he was with his head on her knee. Then she untied her apron strings, and slid the apron quietly on to the ground with its burden upon it, and then she took her feet home as fast as it was in her heart [23]. Now when she was getting near the houses, she gave a glance behind her, and there she saw her caraid (friend) coming after her in the likeness of a horse.'
The equine form belongs also more or less constantly to the kelpie of the Lowlands of Scotland and of the Isle of Man, where we have him in the glashtyn, whose amorous propensities are represented as more repulsive than what appears in Welsh or Irish legend: see p. 289 above, and the Lioar Manninagh for 1897, p. 139. Perhaps in Man and the Highlands the horsy nature of this being has been reinforced by the influence of the Norse Nykr, a Northern Proteus or old Nick, who takes many forms, but with a decided preference for that of 'a gray water-horse': see Vigfusson's Icelandic-English Dictionary. But the idea of associating the equine form with the water divinity is by no means confined to the Irish and the Northern nations: witness the Greek legend of the horse being of Poseidon's own creation, and the beast whose form he sometimes assumed.
It is in this sort of a notion of a water-horse one is probably to look for the key to the riddle of such conceptions as that of March ab Meirchion, the king with horse's ears, and the corresponding Irish figure of Labraid Lorc [24]. In both of these the brute peculiarities are reduced almost to a minimum: both are human in form save their ears alone. The name Labraid Lorc is distinct enough from the Welsh March, but under this latter name one detects traces of him with the horse's ears in Wales, Cornwall, and Brittany [25]. We have also probably the same name in the Morc of Irish legend: at any rate Morc, Marc, or Margg, seems to be the same name as the Welsh March, which is no other word than march, 'a steed or charger.' Now the Irish Morc is not stated to have had horse's ears, but he and another called Conaing are represented in the legendary history of early Erin as the naval leaders of the Fomori, a sort of position which would seem to fit the Brythonic March also were he to be treated in earnest as an historical character. But short of that another treatment may be suspected of having been actually dealt out to him, namely, that of resolving the water-horse into a horse and his master. Of this we seem to have two instances in the course of the story of the formation of Lough Neagh in the Book of the Dun Cow, fo. 39-41:--