XXU INTRODUCTIOX. 



DIVISION OF THE AREA INTO DISTRICTS. 



It has been already stated that the number of the rivei'S is one of the 

 noticeable features of the area. It is easily divided into Districts by 

 marking out their respective basins, or rather portions of basins ; for in 

 most cases it is not an entire one that comes within the line of limit, 

 passing at twelve miles distance from the town of Plymouth. By means 

 of these basins, or portions of basins, six Botanical Districts are formed ; 

 I. and II. in East Cornwall, iii., iv., v. and vi. in South Devon. Although 

 the larger part of the area is in South Devon, and the smaller in East 

 Cornwall, it has been thought best to take the Cornwall portion first in 

 order, so as to fall in with the sequence of the two vice-counties " East 

 Cornwall " and " South Devon," in Topograxihical Botany." In that work 

 East Cornwall appears as vice-county 2, South Devon as vice-county 3. 

 The six Districts are named as follows : 



East Cornwall . i. Notter. 



II. West Tamar, 



South Devon . . iii. East Tamar and Ta^'y. 



IV. Plvm. 

 v, Yealm. 

 VI. Erme. 



Each District will be found clearly defined in the accompanying map. 



East Cornwall. I. Notter. — The boundary lines of this are : north and 

 west, the line of limit to the area ; south, the English Channel ; east, the 

 turnpike road from Callington to one mile north of Saltash, thence a line 

 drawn a little east of St, Stephens village on to the eastern shore of Forder 

 Lake, and continued across the estuary to follow the road from Antony 

 Ferryhouse to Tregantle Fort, and pass west of it to the Channel at Whit- 

 sand Bay. The small portion of country dramed by the little river Seaton is 

 included m this Distiict, being thought too small to constitute a separate 

 one. The Tidy has been considered a tributary of the Notter. This 

 District has a very diversified surface. In the north there is a consider- 

 able extent of unbroken connnon, and woods and copses occur ui various 

 spots. In the south, about St. Germans, Sheviock, and Landrake, there 

 is a great deal of good arable and pasture land. The alluvial and sandy 

 ground by the estuary of the little river Seaton produces several interest- 

 ing plants. The following species are found only in this District : 



