Transactions. 253 



The seaweeds found along the shores of Dumfriesshire and 

 Galloway have not, as far as I am aware, been catalogued, and 

 although they are not so varied or plentiful as those on more 

 exposed coasts they form a portion of the flora of the district and 

 should not be overlooked. 



Seaweeds are found in greater abundance on the rocky and 

 exposed coasts, in the pools of water among the rocks, and growing 

 in the water when the tide is at the ebb. As there are no rocks 

 along the coast of Dumfriesshire, but sand banks instead, and the 

 distance to the water's edge when the tide is out considerable, only 

 a few specimens can be obtained growing in the natural state, and 

 not many are to be gathered when washed ashore by storms. 

 The Galloway coast differs from that of Dumfriesshire, for there 

 are rocks at Douglas Hall, Colvend, and further westward, but 

 these are either of the Silurian or Igneous formations, and are not 

 so favourable to the growth of seaweeds as the softer rocks. 



In order to investigate the seaweeds of the district it is 

 necessary to examine the rocks or other structures where they 

 grow at all seasons of the year, and every opportunity should be 

 taken to collect specimens washed ashore by spring tides and 

 storms. Under these circumstances the making of a complete list 

 of seaweeds is no easy task, and as the spare time at my disposal 

 was limited, I have only been so fortunate as to secure some of the 

 commoner species, many of which I now exhibit and briefly notice. 



Sub-Class I. — Melanospermece. — The seaweeds in this sub- 

 class are of an olive colour and grow in abundance on every shore, 

 except one genus — Sargassum — which covers immense tracts of the 

 Atlantic in the tropics. This sub-class is divided into six orders, 

 which we shall briefly notice. 



' Fucacea'. — All the plants in this order are dark olive and 

 have the peculiarity of turning black when dry. The following 

 are frequently met with : Halidrys Siliguosa, growing in rocky 

 pools, and at low water mark on the rocks at Douglas Hall and 

 the Galloway coast. Fucits vesicidosus, common sea-wrack, grows 

 on every stone washed by the tide. 



F. Serratiis, common, is distinguished by the sorrate fronds, 

 no air vessels, and grows in large patches on the rocks between 

 tide marks. F. Nodostis, also common, generally washed ashore at 

 Glencaple and Euthwell by the tide. A number of parasitical 

 species attach themselves to this plant. F. Canaliculatiis, a small 



