76 Proceedings of the Royal Society of Edinburgh. [Sess. 



is more or less peaty. In lowland non-peaty lochs that receive the 

 drainage from cultivated land, M. spicatum as a rule takes its place. 

 It is exceptional to find the two species in the same water. 

 Myriophyllum spicatum, L. " II.," V., VI., VII. Abundant where the 

 water is not peaty ; see remarks on the preceding species. 



CALLITRICHACEtE. 



Callitriche vernalis, Koch ( = C. 'palustris, L.). VI., VII. Rare at the 

 lochs, but it sometimes occurs in sheltered bays or in shore pools. 



Callitriche stagnalis, Scop. " I., III.," IV., V., VI., VII. Terrestrial and 

 aquatic forms are rather common in shallow places and pools about 

 the shores of non-peaty lowland loclis. When growing on a muddy 

 or sandy shore the plants are rather sturdy, and form sward-like, 

 spreading tufts. When submersed they are weaker, with leaves and 

 internodes elongated. 



Callitriche hamulata, Kiltz. ( = C. intermedia, Hoffm.). " I., III.," IV., 

 v., VI., VII. Widely distributed in peaty lochs, but nowhere so 

 generally abundant as in Area I. It is usually found without the 

 floating rosettes, but in a few places. Loch Stroan for example, the 

 two forms occur. W^hen rosettes are present, the floating, spathulate, 

 apical leaves gradually become transformed downwards into the 

 linear type, and from about 3 inches below the apex all the lower 

 leaves are linear and emarginate, as in the form without the floating 

 rosettes. 



Callitriche autumnalis, L. V., VI., VII. This fine species is widely 

 distributed in non-peaty lowland lochs, and is frequently very 

 abundant. At Soulseat Loch, for example, this plant and Ranun- 

 culus circinatus are the only submerged Phanerogams that are 

 plentiful. Again, at Carlingwark and Kilconquhar Lochs, notwith- 

 standing strenuous competition by more robust rivals, this plant 

 maintains a dominance over certain portions of the bottom. This 

 species varies somewhat in the form of leaf and fruit. 



PORTULACE^. 



Montia fontana, L., and its aquatic form, var. rivularis, Gemel. " I., 

 II.," v., VI., VII. A very common plant about the shores of some of 

 the less peaty lochs in both aquatic and terrestrial foi-ms. 



SAXIFRAGACE.^. 



Parnassia palustris, L. " L, II.," IV., [V., VI.— J. M'A.], VII. Occasion- 

 ally represented on boggy shores. 



