LINNEAN SOCIETY OF LONDON. 85 



the half dozen names he quotes it appears that he meant species 

 which outside the British Isles were, as he thought, confined to 

 the Pyrenees or the North of Spain or the Iberian or Pyrenean 

 peninsula generally. 



So much as to Watson's term " Atlantic type " and the more 

 loosely used descriptions Norman, Asturian, Iberian, Lusitaniau 

 and Pyrenean. 13ut what, then, is that Southern element which 

 undoubtedly is present in the British flora and has so early attracted 

 the attention of British botanists by its peculiar distribution, 

 mostly westward, frequently much interrupted and in many cases 

 extremely limited ? If we take a British flora, for instance the 

 last edition (1904) of Babington's ' Maniial,' and a flora of 

 Germany, like Ivoch's 'Flora Germanica,' ed. III., whose area 

 after the deduction of the Mediterranean districts in Switzerland 

 and Austria and parts of the extreme West is practically that of 

 Central Europe, and if we mark off in the British flora those species 

 which are not recorded from Central Europe as defined, we obtain 

 a rough list of the plants which do not partake in the composition 

 of the flora of Central Europe. Of these a small number is 

 peculiar to Northern Europe, or, outside Great Britain and Ireland, 

 only known from North America ; these may be struck off. If 

 we further revise with the help of the latest floras the distx'ibu- 

 tion of the species remaining on the list partly to exclude errors, 

 and partly to add such British species as in isolated cases enter 

 the Central European region either from their headqura'ters in the 

 west or south, we shall have left an assemblage of about 150-160 * 

 species (9 per cent, of the British flora), the European con- 

 tinental areas of which lie mainly along the west coast of Europe 

 from Holland and Belgium or from Normandy to Spain and 

 Portugal, or beyond those countries to Italy and even the Orient 

 (Map ], inset). They fall into two fairly distinct classes. That 

 set which does not extend into the eastern Mediterranean region 

 (Map 2, inset) may be called for the purposes of the paper the 

 Atlantic element, the other the Mediterranean (Map 3, inset). 

 The Atlantic element extends in Belgium and France more or less 

 eastward, but crosses the Kliine or the Rhone only in exceptionnl 

 cases. A few species referred to it reach North Italy, but out- 

 side the typically Mediterranean region. A few also extend along 

 the west coast to Denmark or Norway, but they have in each case 

 their main area farther south. 



In my original paper the species of the " Southern Element '^ 

 wei'e grouped in three classes — namely : 



1. Species generally found in and near cultivated land. 



2. Species confined to the coasts (littoral species). 



3. Species other than those referred to classes 1 and 2 (they 



might be termed translittoral or inland species). 



* The species of Rosa, Enhus, and Hieracium have not been taken into con- 

 sideration owing to the difficulty of a satisfactory collation of the speciea 

 recognised by British and Continental authors. 



