PREFACE. 
The last edition of the Catalogue of this Collection was published in 1839. In J843 the Author 
removed from the city of New York to his present residence at Rye, Westchester Co., N.Y., where he 
has re-arranged the Collection in the same order with this Catalogue. While thus occupied, the 
opportunity was emhraced of compiling this edition by the re-examination of the specimens and their 
descriptions, without any regard to the last edition. 
It wdll be observed that the Collection has increased more than threefold, which has rendered it 
necessary to re-number the Catalogue. 
This has been achieved, in part, by the liberal contributions of numerous correspondents, and in 
part by purchase, and chiefly from the collection of Hugh Cuming, Esq., of London. The same 
systematic arrangement has been followed, modified, however, by the recent discoveries of many of 
the Mollusca, hitherto unknown. 
Most of the modern Genera are introduced in their proper places, and will be found by a reference 
to the Index. 
The Species are arranged for convenience in alphabetical order, to which are added their Varieties, 
Authors, Habitats, and Synonymes, as far as it was practicable. 
References to figures and descriptions of each species, and of most of the varieties, are given, the 
Author having especially consulted the recent works on Conchology. 
The fourth column contains the numbers of the species, or page of the second edition of Lamarck’s 
Animaux sans Vertebres, par Monsieur Deshayes, excepting in the Families of the Colimacea and 
Cyclostomacea, where they show the grouping of the species after the arrangement of Monsieur Louis 
PfeifTer. In the Index will be found the names of all the Genera and Families, and also the Synonymes 
of the Species. 
A list of the works on Natural History in the Cabinet is also added, that Correspondents and others 
may see whether it contains their memoirs, and if not, they will confer a favor by forwarding them in 
exchange for the Catalogue, or anything else they may designate. 
All the Species not enumerated in the Catalogue will be thankfully received (in exchange), 
provided they are accompanied hf a list of “ Desiderata.” 
JOHN C. JAY. 
Jiye, Westchester Co.^ N. T., U. S. America. 
December, 1850. 
