of the North of Ireland. 59 
Where practicable, I have preferred giving verbatim quotations from the 
authors quoted, in place of a general summary of their remarks. 
Of the 404 British species contained in that portion of the Suh -Kingdom 
Mollusca, as described by Jeffreys, to which the present paper refers {i.e. the 
classes Brachiopoda , Conchifera, Solenoconchia , and Gasteropoda to the end of 
Pleurobranchiata ), our district has yielded 291, or very nearly f— 1 1 9 bivalves 
and 172 univalves — exclusive of such species as are importations or fossils, and 
which are printed inside brackets. On the whole, the Fauna has a northern 
aspect, since, of these 291 species, 36 are boreal forms, which live either not at all, 
or very sparingly, south of Britain, while only 12 are essentially southern, having 
been taken seldom or never north of the British coasts ; the remaining 243 inhabit 
seas both north and south of our islands. As is to he expected from geographical 
considerations, the southern species frequent chiefly the western shores of the 
province, while the northern forms have been mostly taken on the eastern coast. 
Of the northern types, Crenella decussata, Leda minuta, Tectura testudinalis , 
E mar g inula crassa, Trichotropsis borealis , and Trophon truncatus , will serve as 
examples — they have all been taken alive in our waters ; while the following 
will serve as representatives of the southern forms which the district yields — 
Modiolaria costulata, Crenella rhombea , Area lactea , Troehus Duminyi , Natica 
sordida , Ovula patula. 
Only one species is, as a British shell, confined to our province — Troehus 
Duminyi ; it occurs on the western coast, and is a southern shell, its foreign 
stations being all Mediterranean. 
The Testacea of the counties of Antrim and Down may he considered as 
pretty well worked up, though the North of Antrim offers a good field that has 
been scarcely touched. County Londonderry contains extensive sandy beaches, 
which yield a large variety of species, that of Magilligan especially ; here the 
observations have been chiefly made from shore, and dredgings in the deeper 
water might yield interesting results. I find no record whatever of any dredging 
in Lough Foyle. From the extensive coast-line of County Donegal, with its 
magnificent headlands and deep inlets and sandy hays, comes hardly a single 
note to enrich the list which follows. At Bundoran, indeed, in the extreme 
southwestern corner of the county, Mrs. Hancock made many finds, which she 
communicated to Thompson; and here Mr. Waller discovered a new British 
Troehus , T. Duminyi, whose only British station is still Bundoran ; but beyond 
these, the conchology of the most northern county of Ireland still remains to be 
investigated, and will probably amply repay the investigator. 
Mr. Thompson appears to have placed but light value on the condition 
(living or dead) of the shells which he found in his dredgings, or thrown up 
by the tide, and in many instances does not mention this point at all. In the 
present paper the writer perhaps has erred in the opposite extreme, and has 
plqced undue importance on this point, but it does appear to him to be of 
interest and importance to know whether or not a shell has been taken living in 
the district. It is to be remembered, however, that the fact of a species not 
having been found living, is by no means positive proof that it no longer 
