114 TRANSACTIONS OF THE [Sess. lxxxvi 



Orcadensis," p. 72 (1914), where the record " Stromness 

 (1910; Dr. Grant)" is an error; and "Trans. Bot. Soc. 

 Edin.;' vol. xxviii, p. 57 (1920). 



PoTAMOGETON PRAELONGUS, Wtilfen. (name confirmed by 

 Arthur Bennett). — Mud at bottom of water, 1| foot deep, 

 in old quarry holes in the bed of a loch near the shore, 

 13 feet above sea-level, north-east and south-west of the 

 windmill pumping station (formerly a boat-house), Loch of 

 Tankerness, Saint Andrews, Mainland. Native. Rare. 

 Plants not in flower or fruit. Confirms the record of this 

 species from Orkney (" Locli of Tankerness ") by the late 

 Mr. Magnus Spence in his '• Flora Orcadensis," p. 71 (1914). 



POTAMOGETON HETEROPHYLLUS, ScJireh., form GRACILIS 



(Wolfg.) [ = PoTAMOGETON WoLFGANGii, KHilman] {fide 

 Arthur Bennett). — Mud at bottom of water, 4 feet deep, in 

 a loch, 13 feet above sea-level, Loch of Tankerness, Saint 

 Andrews, Mainland, 19th July 1883 and 12th August 1921, 

 H. H. Johnston. Native. Common. Plants in flower, 

 without any floating leaves. A new record for this form 

 for H. C. Watson's county No. Ill Orkney. I have a 

 specimen of Potamogeton heterophyllus, Schreb. {fide 

 Arthur Bennett), with floating leaves, collected by me, in 

 the Loch of Tankerness, on 12th August 1921. 



Potamogeton heterophyllus, Schreb., var. intermeditts 

 (Tiselius) (fide Arthur Bennett). — Mud at bottom of water, 

 5 feet deep, in a loch, 49 feet above sea-level. Loch of 

 Kirbister, Orpliir, Mainland, 9tli August 1878 and 30th 

 August 1880, H. H. Johnston. Native. Common. Plants 

 in fruit, witli and without fioating leaves. Confirms the 

 record of this variety from Orkney (Loch of Kirbister), in 

 " Scot. Nat," No. i, new scries, p. 24 (July 1883). See 

 "Bot. Exch. Club Report for 1880," p. 36 (1881), with 

 reference to a " form with broad-based submerged leaves," 

 of Potamogeton HETEuoPHYLr.us, Schreb., collected by the 

 late Dr. J. T. L B. Boswell, in the Loch of Kirbister, in July 

 1875; "Journ. Bot.," vol. xxxix, p. 273 (August 1901); 

 " Annals Scot. Nat. Hist.," No. 71, p. 180 (July 1909) ; and 

 Spence, " Flora Orcadensis," p. 73 (1914). 



Potamogeton nitens, Weber, var. subgramineus, 

 Haf/strom, forrn stenobasis, Hagstrihn {fide Arthur 

 Bennett). — Mud at bottom of nearly fresh water, 3 feet 



