The Scottish Naturalist. 25 



" Kirbuster Loch, Orphir, Orkney, August, 1880," J. T. 

 Boswell. 

 Potamogeton picsillus, L., var. rigidus, mihi (A. Bennett). 



Plant rigid, fragile, leaves rigid, 1^ to 2J inches long, long bud 

 acuminate, strongly 1 nerved, with 2 fainter nerves in some of 

 the leaves, stipules long acute, peduncles 1 inch long, spike 

 \ inch long, fruit slightly smaller than in typical pusillus, and 

 less carinated on the back. 

 A remarkable form of pusillus, gathered by Dr. Trail from the 

 Loch of Stennis, Orkney, August, 1876. It has much the 

 aspect of P. rutilus, Wolfgang, but differs by its elongated 

 internodes, broader leaves, stipules and fruit. 

 P. pectinatus, Z., genninus. 



"Loch of Kirbuster, Orphir, Orkney, August, 1880," J. T. 

 Boswell. 

 P. rufescens, Schrad. 



Might occur. I have it from the Wick River, Caithness. 



Zannichellia L. 



343 polycarpa Nolte., B. Loch of Kirbuster, Mill Pond, Swan- 

 bister. 



Ruppia L. 



344 spiralis Hartm., B. Bridge of Broigar. 



345 rostellata Koch., B. Fidge, Swanbister. 



v. nana. Eus Firth, B. 



Zostera L. 



346 marina L., B. Common. 



v. angustifolia. Eus at Firth, B. 



ALISMACE^. 

 Triglochin L. 



347 palustre L., B. Common. 



348 maritimum L., B. Common. 



ORCHIDACE^. 

 Orchis L. 



349 mascula L. Sea banks Birstane, Lingro, D. Above Westness, 

 Rousay, Dr. Traill. 



350 latifolia L., B. Common. 



351 maculata L., B. Common. 



Gymnadenia Br. 



352 conopsea Br. Scalpa B. ; Caldale, D. and H. 



