Stewart — List of Estuarine Clay Fossils. 31 
Purpura lapillus. A few specimens occurred, but this species may be 
reckoned among the rare shells of the Estuarine Clay. 
Buccinum undatum. Very common. 
Murex erinaceous. Rare at Belfast, rather frequent at Larne. 
Fusus antiquus. Occurs occasionally, but not at all common. 
Nassa reticulata. Frequent throughout the Clays. 
Nassa pygmea. Very common. Mr. Grainger’s N. incrassata belongs, I 
believe, to this “ segregate.” The distribution of these forms in our 
local Post-tertiary deposits seems to have been very fluctuating. 
Nassa incrassata occurs in our Glacial Clays, then disappears from our 
subsequently deposited Estuarine Clay, and finally reappears as the 
dominant form in our existing waters. Nassa pygmea , on the other 
hand, has not been found in our Boulder Clay, but in the Estuarine 
Clay is abundant, and now again ranks as a rare shell confined to 
the deep waters outside the bay, 
Defrancia gracilis, Mangelia gracilis. F. & H. Very rare, one speci- 
men only. 
Pleurotoma cost at a, Mangelia costata. F. & H. One specimen, (fide 
Grainger). 
Pleurotoma brachystoma, Mangelia brachy stoma. F. & H. Rather 
rare. 
Pleurotoma septang.ularis, Mangelia septangularis. F. & H. Very 
rare. 
Pleurotoma rufa, Mangelia rufa , F. & H. “ Belfast deposit” (J. Gwyn 
Jeffreys). By the Belfast deposit, I believe Mr, Jeffreys means our 
bed of Estuarine Clay. Nevertheless, few discriminate sufficiently 
between the Estuarine Clay and the raised beaches occurring here. 
The latter I have excluded from my list. 
Pleurotoma turricula, Mangelia turricula. F. & H. Rare. 
Cypr^a Europ^a. Two or three specimens only of our British cowry 
occurred to me. 
Cylichna nitidula. In the Belfast bed I found one shell. 
Utriculus obtusus, Cylichna obtusa. F. & H. In the Larne, and also 
in the Strangford Lough Estuarine Clay, rare. 
Utriculus hyalinus, Amphisphyra hyalina , F. & H. Plentiful in the 
Belfast and in the Larne^beds,but so fragile that specimens can scarcely 
be secured. 
