8 
Silene cornea, Potamogeton zostersefolius, and Carex Gibsoni. 
Examples of the class of species which are probably correctly 
reported, may be found in Centaurea calcitrapa, Aceras anthropo- 
phora, and Carex brizoides. 
One of the most important generalizations which has been established 
through the onward progress of geographical botany, is, the subdivision 
of the British flora into “ types of distribution,”* according as the species 
are more or less generally diffused over the whole extent of the island, 
or are limited to, or preponderate in, some particular section of its sur- 
face. In order to afford a means of estimating the relations of the flora 
of Yorkshire to that of other portions of Britain, on the right hand side 
of the line is placed the name of the type to which each species may bo 
considered to belong. The types of distribution are thus named and 
made up. 
1. British Type. — Species which are more or less generally diffused 
throughout the whole, or nearly the whole, extent of Britain. 
Examples : Sagina procumbens, Senecio vulgaris, Thymus serpyl- 
lum, Lastrea dilatata. 
2. English Type. — Species which have their head quarters in England, 
especially in the southern provinces, and become rare and finally 
cease altogether towards the north. Examples : Rhamnus catharti- 
cus, Pulicaria dysenterica, Convolvulus sepium, Tamus communis. 
3. Scottish Type. — Species which, contrary to those which make up the 
last type, have their head quarters in Scotland or in the northern 
provinces of England, and become rare and finally cease altogether 
southward. Examples : Trollius europeus', Campanula latifolia, 
Gnaphalium dioicum. 
4. Highland Type. — The boreal flora in a more intense degree. Species 
which have their head quarters amongst the Scotch Highlands, and 
are only found southward in the vicinity of elevated mountains. 
Examples : Draba incana, Rubus chamsemorus, Myosotis alpestris. 
5. Germanic Type. — Species which have their head quarters in the south- 
east of England, and run out northward and westward. Examples : 
* These were first defined in Watson’s “ Remarks on the Geographical Distribution of British Plants,” 
published in 1835. They are fully explained in the same author's “ Cybele Britannica,” vol. i. pp. 43—55, 
and under each species in detail. 
