30 INTRODUCTION. 
more of the adjacent provinces. And others, again, run far up 
the western coasts in a northerly direction, often plentifully there, 
and yet occur rarely, or not at all, towards the eastern coasts of 
the island. These species, while thus dissimilar in their area and 
census, correspond in the one circumstance of having some evident 
tendency to the western or Atlantic side of the island, in contra- 
distinction to the eastern or Germanic (sea) side. Although there 
may exist other grounds for specially designating some of these 
the “ Atlantic species,” the name of the type will be here under- 
stood in reference only to their distribution within Britain itself, 
and by itself. As examples we may cite Sinapis monensis, 
Matthiola sinuata, Raphanus maritimus, Sedum anglicuin, Coty- 
ledon Umbilicus, Bartsia viscosa, Pinyuiculu lusitanica, Euphorbia 
portlandica, and Scirpus Savii. More strictly local examples are 
found in Sibthorpia europea, Erica ciliaris, Polycarpon tetraphyl- 
lun, Adiantum Capillus-Veneris, and Cynodon Dactylon, each 
occurring in very few counties. 
7. A Local or Doubtful Type. — Dispersed about the island, 
there are some species whose area includes only single or few 
counties. Such plants can seldom exhibit that decided tendency 
to the east or the west, to the south or the north, to the mountains 
or otherwise, which would fully warrant their assignment to any 
one of the six preceding types of distribution. In those instances 
where the single or few localities occur clearly and solely within 
the geographic limits of one of the types, the plants will usually be 
associated with the group to which they thus make the nearest 
approximation. There can be no hesitation, for example, in 
assigning to the Highland type the extremely local Oaytropis 
campestris and Lychnis alpina, both mountain species; and 
scarcely more doubt can arise in placing Arenaria norvegica of 
Shetland, and Primula scotica of the two most northerly pro- 
vinces, among plants of the Scottish type. So also, the local 
Cicendia filiformis may join in with the English type; Veronica 
verna, with the Germanic type; Erica vagans, with the Atlantic 
type. But after thus disposing of a large portion of these very 
local plants, there still remain some others which cannot be so 
