802 Dr. G. Dickie on the Altitudinal Range : 
someter) was guessed as being not under 1400 feet, and upwards 
of fifty miles inland from Aberdeen. . 
Grimmia spiralis. Has not been seen in this county lower 
than 2200 feet ; the upper limit is unknown to me. 
G. torta appears on cliffs in the vicinity of Ballater at 1400 
feet ; I have observed it in Glen Callater at 2300 feet, but cannot 
state its absolute highest limit. 
G. ovata appears on the hill of Fare at 600 feet; I have also 
seen it on the top of Noath at 1830 feet ; it grows on the inside 
of the wall of the vitrified fort. In general outline this ruin is 
élliptical; the walls are vitrified on the inside, and inclose.a smooth 
grassy surface at the very summit of the hill. The wall is de- 
ficient at the east side ; the species in question is mostly confined 
to the inside of the wall at the west end, and consequently oppo- 
site the opening alluded to. Are we to conclude that the seeds 
of the plant had been conveyed by the wind from some distant 
locality ? for I did not see it on any other part of the hill. i 
Tortula tortuosa occurs on serpentine, near Ballater, at 1800 
feet of elevation. 
POLYTRICHUM. 
All the British species grow in this county. 
In the immediate vicinity of Aberdeen the following species 
are found: Polytrichum undulatum, hercynicum, piliferum, juni- 
perinum, commune, urnigerum, aloides, nanum ; of these P. hercy- 
nicum is rarest ; I have seen it sparingly four miles inland on very 
old walls along with Bartramia ithyphylla. Myr. Mackay found 
it more abundant seven miles west from Aberdeen, and it grows 
in considerable quantity about the base of the hill of Fare. In 
the same vicinity, but at an elevation of 900 feet, Polytrichum al- 
pinum grows ini considerable quantity. P. septentrionale is con- 
fined to our higher summits; it is abundant about the top of 
Ben-na-Muich-Dhu. Mr. Mackay informed me that he had 
found it very sparingly on the top of Lochnagar. 
Lowest. Highest. 
Polytrichum hercynicum ... 50feet. 3000 feet (highest ?) 
piliferum ...... 50 1800 i 
juniperinum ... 50 1700 a 
septentrionale... 3800 4000 and upwards, 
alpinum ......... 900 3800 
Entosthodon Templetoni. Has been found in small quantity 
by Mr. Mackay near Ballater, forty-two miles inland, at about 
800 feet. 
Orthotrichum Hutchinsiez. Is rare in Aberdeenshire; I have 
seen it very sparingly in Glen Callater, not lower than 2000 feet, 
_ but cannot state how much higher it attains. 
Bryum julaceum. Grows in considerable quantity a few miles 
