81. FLUVIALES. 15 



1124. PoTAMOGETON CEISPUS, Linn. 



Ai-ea 1 2 3 4 5 6 7 8 9 10 11 * 13 14 15 16 * [18]. 



South limit in Devon, Isle of Wight, Kent. 



North limit in Moray, Ai-gyle. [Shetland ?] 



Estimate of provinces 16. Estimate of counties 70. 



Latitude 50 — 58 [60]. British tj^pe of distribution. 



Agrarian region. Inferagrarian — SuperagTarian zones. 



Descends to the coast level, in the Peninsula. 



Ascends to 100 or 200 yards, in England. 



Range of mean annual temperature 51 — 47. 



Native. Lacustral. The Flora of Shetland appears 

 to be the only au.thority for the existence of this species 

 northward of Moray and Ai'gyle ; and considerable hesi- 

 tation is felt about admitting that single authority for 

 plants so liable to be mistaken as are the species of Pota- 

 mogeton ; more esi^ecially because the Flora of Shetland 

 is known to have been the work of a very young botanist, 

 incautious and somewhat self-confident. 



1125. POTAMOGETON PEEFOLIATUS, Linn. 



Ai-ea 1 2 3 4 5 * 7 8 9 10 11 12 13 14 15 16 * 18. 



South limit in Cornwall, Dorset, Sussex. 

 %/ZA-t^^ North limit in Orkney, Hebrides. 



Estimate of jjrovinces 17. Estimate of counties 70. 

 |P Latitude 50 — 60. British tj'pe of distribution. 



Agrarian region. Inferagi'arian — Superagrarian zones. 



Descends to the coast level, in the Peninsula. 



Ascends to 400 yards, in Humber province. 



Kange of mean annual temperature 52 — 43. 



