84 DISTRIBUTION IN CONNECTION 



the western coasts. The western boundaries of the 

 counties Hants, Berks, Oxford, Warwick, Derby, York, 

 Durham, and Northumberland, run nearly with this 

 meridian. Hence these counties and all to the eastward 

 of them may be called the Eastern Counties, while those 

 lying to the westward will then be the Western Counties. 

 According to the New Botanist's Guide, above a hundred 

 species are limited to the eastern counties of England, 

 and between sixty and seventy species are confined to the 

 western counties, Wales included therewith. Nearly one 

 half of these are peculiar to single counties, and the 

 greater part of the rest occur only in two or three. Such, 

 therefore, cannot with any sense of fitness be singled out 

 as illustrations of the influence of longitude over vegetable 

 distribution. Neither should introduced species be re- 

 ceived as proper examples. The omission of all these 

 very greatly reduces the number of eastern or western 

 species ; and increased knowledge will doubtless remove 

 several of the following from the lists in which they are 

 placed. Each is named under at least four counties, in 

 the first volume of the New Botanist's Guide ; that is, in 

 so many counties of England or Wales. 



Eastern Species. 



Furaaria parviflora. Distribution little known. Likely to occur in 

 the west. 



Frankenia laevis. A good example. On the coast from Sussex to 

 Cambridge, and introduced to Durham. 



Ceratophyllum submersum. Distribution little known. 



Peucedanum officinale. Very scarce. Kent to Notts. 



Tordylium maximum. Possibly introduced. In four inland counties, 

 namely, Middlesex, Herts, Bucks, Oxon. Hence not 

 strictly an eastern species. 



Lactuca Scariola. In 7 counties ; the S. E. of England and Derby- 

 shire. 



