SiGERSON — Fish-rcmains in Allimal Clay of River Foyle. 213 
have been expected, as tlie current running through it was pro- 
bably strong enough to render it an unfavourable habitation for 
molluscous animals: at present, therefore, the subject must be con- 
sidered strong in the evidence of external characters, though as yet 
only partially supported by that of existing organic remains. That 
this valley has probably been a water-course may be judged from the 
following excavations : — 
''1st Excavation, 2ft. 6in. — Surface loam, with pebbles of mica, 
slate, and quartz. 
"2nd Excavation, 2ft. Sin. — The same result as in the 1st; then 
blueish, tenacious clay, with thin gravel. 
" 3rd Excavation, 2ft. 12in. — The same result as in 1st and 2nd; 
then coarse gravel. Underneath, a finer gravel, mixed with sand."^' 
JN^o animal organic remains whatever appear to have been found, as 
none are recorded. However, the thin stratum of tenacious clay which 
he describes seems to have the same nature, origin, and age as the 
alluvial deposit in which, farther up the river, the fish-remains have 
been discovered. The deposit of clay lying on both sides of the present 
river channel, where these remains were found, is incomparably more 
copious and extensive than at Derry, and evidently subsided in the 
quieter waters of a lake, now vanished. The fish-remains were found 
in the following manner, on the right side of the river, about nine 
miles south of the city of Derry, two miles north of Strabane, and half 
a mile east of the present river-current. 
Whilst certain labourers, near the village of Ballymagorry, were 
digging up clay for brickmaking, they came upon some small bones. 
The depth at which they were found was about twenty feet beneath 
the surface of the clay, from which generally a layer of peat, a few 
feet thick, has first to be removed. Pits for brick-clay are to i)e seen 
on the landward edge of a floe-bog, which, extending in breadth for 
some half a mile, is bounded by the Eiver Foyle on the west. On the 
opposite, or Donegal side of the river, a stratum of the same clay is 
to be found. These bones were regarded as forming the skeleton of a 
bird by the labourers, who divided them, as curiosities, among them- 
selves. This proves the exceeding rarity of such organic remains in 
the alluvial deposit in question ; and, so far as I could ascertain, no 
other relic of life had ever been met with in excavating the clay-pits. 
The bones, which are now of a deep chestnut colour, and still re- 
tain some of the clay in their interstices, are manifestly portions of the 
skeleton of a moderately large fish. The determination of the spe- 
cimen is rendered difficult by the imperfection of the skeleton ; but, 
from what attention I have been able to give to the matter, I am in- 
duced to form the following opinion. Belonging as it does to the division 
of Osseous fishes, we must yet exclude both Acanthopterygii and Mala- 
copterygii apodes. The Malacopterygii abdominales give us, as pos- 
sible individuals, the salmon, trout, and pike. The non-discovery of 
*Ordnance Survey of the County of Londonderry. Dublin: Hodges & Smith, 
1837, vol. i., p.. 6. 
