REPORT OR T THE BRACHYTJRA. 
iii 
With regard to the terminology employed in the descriptions of new genera and 
species, I have found the simple divisions of the “regions” of the carapace, long ago 
indicated by Desmarest, and modified by H. Milne Edwards in 1834-40, sufficient for 
all practical purposes. These regions are (besides the frontal, orbital and antennal 
regions, and the epistoma) the gastric, cardiac and intestinal regions, situated in the 
median dorsal line, the hepatic, situated ordinarily behind the orbits and near to the 
antero-lateral margins of the carapace, the branchial regions, covering the whole of the 
postero-lateral parts of the dorsal surface, and the pterygostomian regions, situated on 
the inferior surface, and between the antero-lateral margins and the buccal cavity. The 
description of the carapace and post-abdomen is followed by that of the appendages 
and limbs in regular sequence, a complicated terminology being avoided wherever 
possible. 
AVith regard to the synonymical citations, it has been thought sufficient, as a rule, in 
the case of well-known species, to refer to the original authority for the species and to a 
recognisable figure, also to the latest or principal authority for the group to which the 
species belongs, but the synonyma are occasionally given more fully when there has been 
anything to add or elucidate with regard to them. 
Had health and time allowed, I had hoped to give a complete bibliographical list of the 
works and memoirs relating to the Brachyura, but health, which necessitated the resigna- 
tion of my post in the British (Natural History) Museum, compelled also the abandonment 
of this idea, and I thought it right to place the manuscript of the Report in the hands 
of Mr. Murray for publication. The whole of the systematic part, which had been com- 
pleted as far as the description of the genera and species was concerned, though not 
finally revised for press, w r as accordingly printed off before my health again permitted 
me to return to the subject. I have therefore found it impossible to insert many 
details that would have been desirable regarding the affinities and limitation of the 
various families and subfamilies, &c., and a few errors and omissions occur, which are 
referred to in the list of errata at the end of the Report ; perhaps also the lists of species 
are not in all cases as complete as a thorough revision of the literature would have made 
them. I have to thank the Editor of the Reports, and Mr. T. AVemyss Fulton, M.B., of 
the Editorial Staff of the Challenger Office, for the care that was taken to render the text 
as correct as possible while the sheets were passing through the press. 
The generic descriptions of the earlier part of the Report, relating to the Oxyrhyncha, 
and drawn up when I was much engaged with other work, might, perhaps, have been 
extended with advantage to embrace further structural details, and some of the earlier 
plates are inferior to the later in finish ; nevertheless they will in all cases, it is hoped, 
serve the purpose for which they were intended, namely, to illustrate and identify the 
species ; and my best thanks are due to Mr. R. Morgan for the pains which he at all 
times bestowed upon this work, in which he had had previously but little experience. 
