12 81. FLUVIALES. 



in the Synopsis of Koch, who was not a maker of Vanity- 

 species, nor very ready to adopt them. 



1120, b. POTAMOGETON COMPRESSUS, LiUTl. 



Ai-ea 1 2 3 4 6 * * 8 9 10 * * 13 14 15 16 * 18. 



South limit in Devon, Isle of Wight, Sussex. 



North limit in Orkney ; — Aberdeen, Dumbarton. 



Estimate of provinces 13. Estimate of counties 25. 



Latitude 50 — 60. British type of distribution. 



Agi-arian region. Inferagi-ariau — Superagi'arian zones. 



Descends to the coast level, in England. 



Ascends to 100 or 200 yards, in England. 



Range of mean annual temperature 51 — 46. 



Native. Lacustral. The formula is unfortunately here 

 filled up rather according to the use of a name, than in 

 accordance with any satisfactory knowledge about the dis- 

 tribution of a species. The plant has frequently been 

 considei'ed a broader leaved form of P. pusillus, and oc- 

 casionally perhaps mistaken for P. gramineus. My her- 

 barium possesses only a smgle specunen, wliich was 

 gathered in Shropshire by Mr. J. E. Bowman. 



1121. PoTAMOGETON GRAMINEUS, {"Linn.") Aut. Aug. 



Area 12345*789 10 11 [12] 13 * 15 * * [18]. 

 South limit in Devon, Dorset, Sussex, Kent. 

 North limit in Aberdeen, Forfar, Dumfries. [Lanark ?] 

 Estimate of provinces 13. Estimate of counties 40. 

 Latitude 50 — 58. English type of distribution. 

 Agi-arian region. Inferagrarian — Midagrarian zones. 

 Descends to the coast level, in the Peninsula. 



