114 4. CRUCIFER^. 



Sussex, and Shetland. I remain unaquainted with any 

 evidence or argument sufficing to show that we have more 

 than one species under the two names of parviflora and 

 Vaillantii, after separating micrantha therefrom. 



55. Cakile maritima, Scop. 



Area 1 2 3 4 * 6 7^ 9 10 11 12 13 14 15 16 17 18. '^ ^'^■^^f/^} 



South hmit in Cornwall, Isle of Wight, Kent. 



North limit in Shetland, Orkney, Hebrides. 



Estimate of provinces 18. Estimate of counties 50. 



Latitude 50 — 61. British ty]3e of distribution. 



Agrarian region. Inferagrarian — Superagrarian zones. 



Descends, on the coast level, to the Peninsula. 



Ascends, on the coast level, to the North Isles. 



Range of mean annual temperatin-e 52 — 46. 



Native. Littoral. Pretty frequent all around the coast 

 line of Britain, and probably found in almost everj^ httoral 

 county. Between fifty and sixty of our counties are suffi- 

 ciently accessible to the salt-water tides, for the production 

 of littoral plants ; and accordingly, I take the estimate of 

 " 50" for those species which are supposed to occur in 

 nearly eveiy maiitime county. This estimate may be a 

 few over or a few under trath, in some instances ; but the 

 error would probably be rendered wider by substituting 

 " 40" (which would be nearer to ascertained knowledge) or 

 "60" (which would go beyond what is probable) . As be- 

 fore intimated, it would be only an affectation of exactness, 

 to estimate in units the counties for such species as occur 

 in more than 30 and fewer than 70. 



