ADVERTISEMENT. 
When this Work commenced, it was the intention of the Author to have completed it in 
twelve or fourteen numbers, but the discovery of several new species has rendered this 
impossible, and he will, consequently, be under the necessity of extending- it to nineteen 
numbers, one of which will be published as usual, on the first clay of every second 
month, and the new matter will be introduced in such a manner as not to disturb the sy stematic 
arrangement of the work, which, when completed, will form one volume; to which 
some general remarks on the British Crustacea, and an Index of Synonyms will be added 
Although the Work is to be published miscellaneously, yet the plates are so 
as to enable the purchaser to arrange it systematically, when complete. 
numbered. 
