vi PREFACE. 
concerned, are those by the late Mr. Smith of Jordanhill,* 
and by the Jate Dr. Landsborough,+ whilst that by the Rev. 
A. M. Norman? is by far the most accurate and trustworthy; 
besides these, we have some partial lists, such as that in the 
late Dr. Bryce’s well-known work,§ and in the dredging 
reports published from time to time in the annual volumes 
issued by the British Association. The last addition to our 
knowledge in this department appeared in a handbook|| pub- 
lished in anticipation of the visit of the British Association 
to this city in 1876, and a corrected list of the mollusca 
therein catalogued has since been issued by Mr. David 
Robertson. This latter, however, embraces the whole area 
of the West of Scotland. 
In presence of this already considerable literature bearing 
on the subject in hand, it will perhaps be asked what room 
remains for yet another catalogue? ‘To this it may be 
replied that the lists already existing (with the exception 
of those by Dr. Landsborough and Mr. Robertson) are 
buried in half-forgotten or inaccessible journals; and with 
regard to the two exceptions, the first may be considered, 
without disrespect to the memory of its worthy and amiable 
author, by no means reliable; whilst the second, covering 
as it does the whole of the West of Scotland, does not 
constitute what is here attempted—a guide to the Molluscan 
Fauna of our own firth as limited by a line drawn from the 
south end of Kintyre to the heads of Ayr. 
It is to furnish such a guide that I have ventured to 
prepare the following catalogue, and in doing so have gone 
upon the principle of including no species (as far as the 
* In Memoirs of the Wernerian Society, published in 1838, and since re- 
published, along with other papers by the same author, in ‘‘ Researches in 
Newer Pliocene and Post-tertiary Geology.” Glasgow, 1862. 
+ In ‘Excursions to Arran, Ailsa Craig, and the Two Cumbraes.”’ 
Edinburgh, 1852. 
t A Series of Papers in the ‘‘ Zoologist,” 1857-58-60. 
§ “The Geology of Arran and the other Clyde Islands.” Fourth edition. 
Glasgow, 1872. 
|| ‘‘ Notes on the Fauna and Flora of the West of Scotland,” Glasgow, 
1876. 
