34 
Stewart — List of Estuarine Clay Fossils. 
Lucinopsis undata. Very large, and diffused in immense numbers 
through the clay, except in the very oldest and very newest portions 
of the bed. 
Tellina Balthica, Tellina solidulct , F. & H. Abundant, especially near 
the upper surface. 
Tellina tenuis. Near the top, only sparingly, and of small size. 
Tellina squalida, Tellina incarnata , F. & H. Very rare. The only 
specimens I have seen were single valves collected by the late Wm. 
Thompson, Esq., and by Mr. William Darragh, of the Belfast Mu- 
seum. 
Psammobia Ferroensis. Single valves frequent, perfect specimens 
rare. 
Psammobia vespertina. Mr. Grainger records finding 'a single valve of 
this species. 
Mactra subtruncata. Frequent, variable in size and shape. 
Mactratruncata. Scarce. 
Lutraria elliptica. Frequent. 
Lutraria oblonga. One specimen, (fide Grainger). 
Scrobicularia alba, Syndosmya alba , F. & H. Scattered through the 
clay in immense numbers. 
Scrobicularia piperata. Occupies the lower zone of the clay in the 
greatest profusion, Rare oi absent from the ^higher or more recently 
deposited portion of the bed. 
Solecurtis antiquatus, Solecuytis coarctatus , F. & H. A single speci- 
men, ( fide Grainger). 
Solen pellucidus. Distributed through the ^median portion of the bed 
in abundance. 
Solen ensis. Occurs sparingly. 
Solen vagina, Solen marginatus, F. & H. Rather frequent. 
Thracia papyracea, Thracia phaseolina. Frequent ; shells often perfect. 
The form T. villosiuscula also occurs. 
Thracia convexa. Perfect specimens of this fine shell are plentiful ; 
their occurrence made it easy to recognise a well-marked zone of the 
clay, replete with species that live mostly at a depth of five to ten 
fathoms. 
Thracia pubescans. One specimen. (Grainger). 
Corbula gibba, Corbula nucleus, F. & H. Plentiful, but mostly as single 
valves. 
