154 PERNS OP GREAT BRITAIN. 



of wMch had previously existed there. Its vegetation 

 was the common products of such places, excepting that 

 the larger portion of it was densely covered with its 

 usual crop, the Smooth Horse-tail. This constituted 

 the food of these creatures, and the noise made by their 

 champing it we could distinctly hear in the evening at 

 many yards' distance." 



4. IE. Machdyi (Mackay's Rough Horse-tail, or Long- 

 stemmed Horse-tail). — Stem simple, or very slightly 

 branched, rough ; sheaths close ; teeth slender, not fall- 

 ing off. This plant, which occurs in mountain glens in 

 Scotland, and in the north of Ireland, is a slender and 

 almost unbranched species, the fertile and barren fronds 

 being alike, save that the former- bears a cone. The stems 

 of the fronds arise from a branched rhizome, and are 

 erect, and from two to four feet high. When they hap- 

 pen to be branched the branches are few, and are chiefly 

 on the lower part of one or two of the side stems. 

 The stem is deeply furrowed, having a double row of 

 raised points along the edges, and the furrows vary 

 from eight to fourteen in number. The sheaths, which 

 clasp the stems very closely, are, like them, marked 

 with lines, and terminate with the same number of 

 teeth. These are very narrow, awl-shaped, black, with 

 thin white margins. The black oblong catkin has 

 a little point at the top, and its scales are about thirty 

 in number. 



This plant was first discovered in 1833 by two 

 botanists, Dr. Mackay and Mr. Whitla, in Colin Glen, 

 near Belfast. It has since been found in the Den of 

 Airly, in Forfarshire ; and on the banks of the Dee, in 



