84 Shells as evidence of the Migrations. 
very probable from the discovery of the shell of the 
fresh-water pearl-mussel (dJ/argarttana margarttifera) 
associated with human remains in the sepulchral cave at 
Perthi Chwareu, near Llandegla, Denbighshire.” 
The presence of fragments of pearl-shell in the paste 
of early hand-made pottery may also be an indication 
that the Early Britons considered the shell as auspicious 
and consequently adding further value to their product, 
analogous to the use in India of lime obtained by burn- 
ing both chank and pearl oyster shells. It is significant 
how widely spread are both these customs. The shells 
of Uno are recorded from North American Indian graves 
where they had been placed to serve as food for the dead 
during the journey to the land of spirits ; and fragments 
of Unio shells were used by the Indians to temper the 
clay for pottery. Beads of Uzzo shell have also been 
found in graves in the neighbourhood of Bulawayo, 
Rhodesia, as already stated. 
An interesting survival of the Greek word tpiyAnva 
(triple drops or beads, ze., pearls) seems to exist in the 
Welsh g/amm (bead), the name having been carried to 
Britain by Phoenician traders.“ It is well known that the 
Phoenicians, after founding many colonies in the 
Mediterranean, passed on through the Straits of Gibraltar, 
and in course of time probably reached the British Isles. 
Here no doubt they became acquainted with the pearls of 
the British rivers. 
The principal fresh-water pearl fisheries in the British 
Isles are those of the Conway River, in North Wales, 
where it is supposed Cesar obtained his pearls; the Irt, 
in Cumberland ; the Tay, Earn, and Teith, in lerthshire ; 
the Dee, Don, and Ythan, in Aberdeenshire; the Spey 
*2 J, W. Jackson, Lancashire Naturatist, Dec., 1913, pp. 321-2. 
*® Kunz and Stevenson, of. cf/, p. 8. 
