GASTEROPODA. 5] 
they give to the complete shell being very different. Mr. A. Bell gives C. reticulatum from 
the Red Crag of Walton (‘ Ann. and Mag.,’ September, 1870), but I have not seen the 
specimen, and imagine that it may probably be the variculosum of that locality. 
CrritHium tricinctum, Broc. Crag Moll., p. 69, Tab. VIII, fig. 1, @ and 4. Supple- 
ment, Tab. IIT, fig. 19. 
Locality. Cor. Crag, Sutton, and near Orford. Red Crag passim. Fluvio-marine 
Crag, Bramerton. Chillesford Bed, Bramerton and Horstead. Middle Glacial, Hopton. 
The above figure, 19, was made from a fragment of this species, which I had obtained 
from the Cor. Crag of Sutton, and it was inserted in order to justify its admission among 
the sheils of that formation. Since the plate was engraved, however, I am glad to say 
that I have obtained three other specimens from the Coralline Crag of the neighbourhood 
of Orford (Gomer pit), one of which is nearly perfect, and would be exactly represented 
by the old figure la, of Tab. VIII, of the ‘Crag Mollusca.’ This species is common in 
the Red Crag and in the Fluvio-marine Crag at Bramerton, as well as in the Chillesford 
Bed at that place. It occurs also, but rarely, in what I consider to be its Fluvio- 
marine representative—the Crag of Horstead, but I have not seen it from the other 
localities of that bed. I have not met with it from the Lower Glacial sands ; but one 
specimen, which fig. 19, of Tab. III, would well represent, has occurred in the Middle 
Glacial sand of Hopton. I do not know it living. 
Mr. Charlesworth has also given me a specimen, too mutilated for figuring of a species 
of this genus, but the characters are not sufficiently distinct for specific determination. 
In this the volutions are more close and numerous than those of C. trecinctum, as were 
remarked to me by Mr. Charlesworth ; it is, I believe, distinct. He obtained it from the 
nodule bed at Waldringfield, and is probably a derivative in the Red Crag. 
Fig. 21, of Tab. IIT, of this ‘Supplement,’ represents an imperfect specimen obtained by 
myself from the Post Glacial Freshwater Deposit at Grays. Mutilated specimens of J/e/ania 
imquinata, and another species of JMJelania, have got into this deposit at Grays, from the 
Hocene Woolwich sands, and the specimen produced may therefore be of similar origin, as 
it resembles Cerithium (Potamides) intermedium, of Sowerby, from those sands (¢ Min. Cor.,’ 
Tab. CXLVII, fig. 3.) I was induced to figure its form, from the difference between the 
character and composition of this specimen, and that of these older tertiary derivatives ; 
the Melanie being strong shells, much abraded, while the specimen figured was so fragile 
that it fell to pieces, leaving only the fragment figured, and disclosed that it was filled 
with the material of the Grays Deposit, and not that of the Hocene one, which at first 
induced me to suppose that it might have been a living denizen of the waters of the 
Grays deposit. I have figured it simply as a shell found in the Grays Bed, without 
venturing to express a positive opinion about it. 
