pretty Heaths (_Erica vagans_ and _E. ciliaris_) are found, the latter spreading to Dorset. They occur in no other stations in the British Islands, and elsewhere only in the Pyrenean region. North Devon is the only home in Great Britain for the handsome Irish Spurge (_Euphorbia hiberna_), which in Ireland is distributed along the west and south coasts, being very abundant in Kerry. Outside the British Isles it also is confined to the Pyrenean area. Crossing into Ireland, we find along the south and west coasts no less than seven plants unknown in Great Britain, and elsewhere found only or mainly in the Pyrenees. Of these, three Heaths (_Erica mediterranea_, _E. Mackayi_, _Dabœcia polifolia_) are confined to Connemara and the Pyrenees; two Saxifrages, the London Pride (_S. umbrosa_) and the Kidney-leaved (_S. Geum_), with their Irish headquarters in Kerry, are likewise confined to the Pyrenean region. The beautiful Large-flowered Butterwort (_Pinguicula grandiflora_, Fig. 28), abundant in parts of Kerry and Cork, grows in South-west Europe and the Alps; while the Strawberry-tree (_Arbutus Unedo_, Fig. 29), so pleasing and unique a feature of the Killarney woods, ranges all along the Mediterranean. A little Orchid, _Neotinea intacta_, found on limy soils in Galway and the adjoining counties, and a Grass (_Schlerochloa festuciformis_) which occurs on sheltered shores on both the east and west sides of Ireland, are likewise confined elsewhere to the Mediterranean region. So it will be seen that along the south-western and western borders of the British Isles there is scattered a well-marked group of plants belonging to the Pyrenean and Mediterranean floras, whose English or Irish stations are quite discontinuous with their nearest Continental habitats. Here clearly is something which calls for explanation; but before discussing the question attention may be drawn to a still more remarkable plant group of our western coasts, which mingles with the southern group referred to.