Dublin Microscopical Club. 229 
the tip of the ear there is a fringe of short whitish hairs. 
Whiskers mostly white, the upper series black, with grey 
tips. The hands and feet are well clad above with whitish 
hairs; below the palms are bare, and the soles are covered 
with fine white hairs. The tail is short and cylindrical, only 
diminishing slightly in calibre towards the tip; it is uniform 
in colour above and below, and is very scantily clad with pale 
isabelline hairs; at the tip of the tail is a pencil of long pure 
black hairs. 
The upper incisors are grooved as usual; the first and 
second upper molars have the transverse ridges forming the 
crowns of the teeth united in the middle, asin G. hurriane, 
G. psammophilus, G. nanus, &c. (hombomys of Wagner), 
and the third upper molar has no second posterior ridge or 
talon, as in G. indicus and G. erythrurus. 
The animal, though not very old, appears to be quite full- 
grown. 
I have failed to identify this specimen with any described 
species of Gerbillus, and have therefore ventured to name it 
after Lieut.-Col. C. Swinhoe, who collected it. 
PROCEEDINGS OF LEARNED SOCIETIES. 
DUBLIN MICROSCOPICAL CLUB. 
January 20, 1881. 
A Black Soot-like Fungus, resembling Torula pinophila, occurring 
on the Stoppers of Glycerine Bottles.—Prof. M‘Nab exhibited a fungus 
found in the Botanical Laboratory at Glasnevin, upon the stoppers 
of bottles containing glycerine. The extremely dilute glycerine which 
moistens the stoppers catches and retains a black soot-like fungus, 
which seems to have some affinity with Zorula pinophila, the 
soot-like fungus of spruce-firs. The subject is one which requires 
more investigation. 
Pitchstone from Dyke near Newry.—Prot, Hull exhibited a thin 
section of pitchstone from the well-known dyke of that rock near 
Newry, which is marked on Griffith’s geological map of Ireland 
(1855), and which (according to Dr. Frazer, who possesses specimens 
of the rock) was first discovered by the late General Portlock. The 
rock is of a dark bluish-grey colour, compact and vitreous, containing 
numerous crystalline grains or blebs of quartz, a few crystals of 
orthoclase (sanidine) sometimes in twins, and a few little black specks 
of magnetite. It is traversed by numerous parallel joint-planes 
dividing the whole rock into plates about 4 inch across. These 
