INTRODUCTION. 
The principal object of the present Catalogue has been to give 
a complete list of all the Crustacea that have been recorded as 
found in Great Britain, indicating at the same time those species 
that are contained in the collection, and pointing out their pecu- 
liarities as regards sex, habitat, and the source from whence the 
specimens were obtained, as far as the materials in the posses- 
sion of the Museum will allow. The locality of the specimens, 
which are not at present contained in the collection, is recorded 
as given by the authority on which they are inserted. 
Those specimens which have been presented to the Museum 
have the name of the donor indicated. Synonyma have been 
added to the orders and other diyisions of the class, as well 
as to the genera and species, with a reference to the work in 
which they have been indicated, and the date, when the 
different names and divisions were first used, is usually added. 
