Stewart— Mollusca of the Boulder Clay. 
171 
Modiolaria marmorata, Forbes. 
Ballyrudder, County Antrim, S. A. S. 
Nucula nucleus, Linn . 
Waterworks, Bryce ; Woodbum, S. A. S. 
Leda pygm^ea, Munst. 
Knock, Woodburn, Ballyrudder, S. A. S. This tiny, delicate shell is not 
uncommon, and almost invariably found in a perfect state. 
Leda minuta, Muller. 
Knock, Waterworks, Woodbum, Ballymdder, S. A. S. Similarly to the 
preceding species, this shell is very often met with in a perfect state. 
Leda pernula, Muller. 
Belfast Waterworks, Bryce; Falls Park, Waterworks, Woodburn, S. A. S. 
My largest specimen attained a breadth of one inch. 
Pectunculus glycimeris, Linn. 
Belfast Waterworks, Bryce. 
Arca pectunculoides, Sacchi. 
Belfast Waterworks, S. A. S. 
Arca lactea, Linn. 
Belfast Waterworks, Bryce. 
Lucina borealis, Linn. 
Woodbum, Ballyrudder, S. A. S. 
Cardium echinatum, Linn. 
Belfast Waterworks, Bryce. 
Cardium nodosum, Turton. 
Belfast Waterworks, Bryce. 
