The Scottish Naturalist. 183 



It is rather curious that Schistidium maritimum grows along with 

 the Myurium, and for the most part at a lower level. I might 

 include a third — viz., Mnium hornum. The Myurium was never 

 found below high water mark, thus affording a presumption that 

 the brackish water was injurious to it ; and yet throughout the 

 Hebrides it never grows far from such brackish water. According 

 to my experience the moss has not been found at a greater 

 elevation above the surface of the water than from 20 to 30 feet. 

 An apparent exception to this rule might be adduced in the case 

 of Loch Coruisk in Skye. As is well known this loch is between 

 40 and 50 feet above sea-level at high water, and its mouth not 

 more than 150 yards horizontally from the sea-beach. 



At a little distance from the'outlet of this loch on both sides the 

 Myurium is found sparingly. It is only where the salt spray during 

 storms can directly find access to it that the moss grows, and even 

 then in a stunted condition. In this situation it is evidently losing 

 its hold, and threatens to become extinct. 



After finding the moss in South Uist, we devoted another day to 

 its detection in Benbecula. We were successful. On stating to 

 our gillie the conditions necessary to its growth, he took us to a 

 loch on the east coast having direct communication with the sea 

 only during spring tides. Here the moss was found under exactly 

 the same circumstances and amid the same surroundings. Stimu- 

 lated with this success, we took an opportunity, on our homeward 

 voyage, to make a run to two lochs near Lochboisdale, but were 

 unsuccessful. To both the sea had direct access with each tide. 

 As we were to be detained in Barra for nearly three hours we 

 agreed to explore a loch on its west coast, whose connections with 

 the sea were reported to be rather distant. We found the moss in 

 great luxuriance, perhaps in the finest condition of all the stations. 

 The water tasted slightly brackish. 



I have now this moss from Skye, North Uist, Benbecula, South 

 Uist, Barra, Teneriffe, and the Azores, i.e., from the Mid-Atlantic 

 Ridge and from nowhere else. 



I shall be happy to supply Bryologists with specimens of the 

 Myurium. 



5 Newton Terrace, Glasgow. 



