112 TRANSACTIONS OF THE [Sess. lxxxvi 



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

 3 feet deep, in a loch, 12 feet above sea-level, Loch of 

 Wasbister, Rousay, 19th July 1921, H. H. Johnston. 

 Native. Common. Plants in flower, and wholly sub- 

 merged in water. A new record for this variety for H. C. 

 Watson's county No. Ill Orkney. 



POTAMOGETON PECTIN ATI IS, Linn., var. UNGULATUS, Hag- 

 strom (fide Arthur Bennett). — Mud at bottom of nearly 

 fresh water, Bay of Islands, Loch of Harray, Stenness, 

 Mainland, 26th September 1921, H. H. Johnston. Native. 

 Common in the channel between Long Holm and the small 

 island immediately to the south-east of it. Plants in ripe 

 fruit. With reference to my specimens, Mr. Arthur Bennett, 

 in a note dated 19th November 1921, writes as follows : — 

 " The rigid lower sheaths and leaves are a characteristic 

 of this." A new record for this variety for H. C. Watson's 

 county No. Ill Orkney. 



POTAMOGETON FILIFORMIS, Nolte, form ALPINUS, Blytt, 

 "Norges Flora," vol. i, p. 370 (1861) {fide Arthur Bennett). 

 — Mud at bottom of brackish water, 5 feet deep, in a loch 

 at sea-level, near the noust for boats. Nether Bigging, 

 Loch of Stenness, Stenness, Mainland, 2nd August 1920, 

 H. H. Johnston ; and shell -sandy mud at bottom of water, 

 about 1 foot deep, in a loch 10 feet above sea-level. Loch of 

 Ptummie, Lady, Sanday, 27th August 1920, H. H. Johnston. 

 Native, common, and plants in flower at both stations. 

 A new record for this form for H. C. Watson's county 

 No. Ill Orkney. 



POTAMOGETON FILIFORMIS, N'olte, form LUXURIOSUS, 



Hagdrom in Neuman's " Sveriges Flora," p. 794 (1901) 

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

 in a loch, almost at sea-level, near the Bridge of Brogar, 

 Locli of Harray, Stenness, Mainland, 24th September 1880, 

 H. H. Johnston ; and mud at bottom of running water, 

 1| foot deep, in a burn, 26 feet above sea-level, Skaill 

 Burn, Sandwick, Mainland, 4th October 1921, H. H. 

 Johnston. Native, common, and plants in ripe fruit at 

 both stations. A new record for this form for H. C. 

 Watson's county No. Ill Orkney. 



POTAMOGETON FILIFORMIS, JSI'olte, form MAJOR, Tiselius, 

 " Exsic. Suec," fas. 3, Nos. 114 and 115 (1897) (fide Arthur 



