160 Proceedings of Societies. 
many places of the boulder clay, and referred to their orders and classi- 
fication, the number of species being as follows :—32 Shells, 15 Uni- 
valves, 17 Bivalves; 1 Balanus; 1 Annelide; 4 Polyzoa; 2 Sponges ; 
1 Coral; 1 Alga—42 total species. Of the shells, 29 are British; 2 Scan- 
dinavian ; 1 Arctic. All the others are British. He stated that the clay 
might be traced all over Caithness, especially in the estuaries and the 
sides of rivers and burns, Some sections showed a depth of 60 or 80 
feet ; while in other places, from low-water mark, it rose a height of 200 
feet and upwards above the level of the sea. It differed greatly in con- 
stitution in the same locality. In some places shells were abundant, with 
very few stones, the clay being pretty soft; in others, stones were 
abundant, shells rare, and the clay so compact that it could not be blasted 
with gunpowder. Occasionally it contained large blocks of stones, such 
as granite, porphyry, gneiss, quartz, &c., some of which contained fossils, 
which were all more or less worn and polished. 
II. Observations on British Zcophytes. By T. Stretmitt Wrieut, M.D. 
III. Notes on Ophrydium versatile. By Mr W. R. M‘Naz. 
Wednesday, 25th March 1863.—James M‘Bain, M.D., R.N., President, 
in the Chair. 
The following Communications were read :— 
I, Notes on some Surgical Homologies. By A. M‘K. Epwarps, Esq. 
il. On the Osteological Homology of the Vertebrate and Articulate 
Classes. Part I.—The Cranium. By Professor Witt1am MacDonatp, 
St Andrews. 
WII. Note of a Fireball, recently observed near Auchterarder. By Joun 
Atex. Smitn, M.D. 
In the beginning of the month of February, a notice appeared of 
the descent of a so-called aerolite upon the farm of Drumtersal, near 
Auchterarder. Lieutenant-Colonel Hunter, who saw the fall, favoured 
Dr Smith with details regarding the phenomenon. The fire-ball fell 
on Tuesday the 27th of January, at five minutes to five p.m. The day 
had been beautifully bright with sunshine ; the sun had set for eighteen 
minutes, it was however still full daylight, when Colonel Hunter’s eye 
was attracted by the descent of a most brilliant luminous body. Its 
fall was nearly perpendicular, and it had the appearance of being the size 
of a twenty-four pound shot. It seemed to fall in a lea field. Colonel 
Hunter’s gamekeeper also saw it, from another direction, apparently 
fall in the same field, and after twenty-four hours had passed, with — 
heavy rain, he went to see if he could discover anything. His eye was 
soon attracted by the peculiar appearance of a stone which lay in the 
place where the meteor seemed to fall. The stone was twelve ounces in 
weight, had a sulphurous smell, and the grass round about it was black- 
ened. Part of the stone was examined by a chemist who recently pub- 
lished the result of his analysis, and stated, among other components, that 
it contained 17°22 per cent. of sulphuret of nickel. 
From the fact of no report of any kind being heard when the ball 
was seen to fall, Dr Smith was very doubtful of any stone-like body 
having fallen,—a loud report generally accompanying the fall of an aero- 
lite. He fancied the ball must therefore have consisted simply of gaseous 
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