VOLUME XXII. 
THE SHELLY DRIFT OF GLENULRA AND 
BELDERRIG, CO. MAYO. 
BY J. DE W. HINCH. 
The earliest information regarding the Shelly Drift of 
north Mayo occurs in a paper read before the Geological 
Section of the British Association in 1875, by W. A. Traill. ^ 
The paper gives a short description of the deposits in 
Glenulra, and at Fiddawtawnanauneen, and mentions the 
occurrence of shells and shell fragments, those identified 
being Tellina proxima, Cyprina islandica, and a Balanus. 
The author disclaims any desire to theorize on the origin 
of the deposits, and only wishes to place on record the facts 
which had come under his notice. A considerable addition 
to our knowledge of the deposits was made during the 
mapping of the sohd geology of the district by H.M. Geo- 
logical Survey. 2 Mr. W. A. Traill reported the occurrence 
of a hard blue compact clay (till) with shells as the lowest 
component of the series. This till occurred in Glenulra, 
Fiddawntawnanauneen, and at Belderrig Harbour, and at 
the last two places Tellina calcarea was found in considerable 
abundance, and with the valves unbroken. 
Above the till was widely-spread brownish Boulder-clay, 
in which at Glenulra and the Owenbehey were found 
numerous shell-fragments. A collection of these was 
1 On the occurrence of a Lower Boulder-clay or Till, with shells, in 
the Counties of Down and Mayo, Ireland. British Association Report, 
1875, pp. 83-84. 
2 Memoir to accompanving shects'39. 40. 51, 52, Geol. Surv., Ireland. 
Dublin, 18S1. 
