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 costata, 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 mfa, 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^ea Europ^ea. 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 liyalina, F. & H. Plentiful in the 

 Belfast and in the Larne|beds, but so fragile that specimens can scarcely 

 be secured. 



