﻿8 BRITISH FOSSIL CRUSTACEA. 



ciently explain the necessity for the commencement of a fresh Monograph, and I am 

 happy to state, that, in undertaking it I have received the approval and kind assistance of 

 my scientific colleagues, both in the British Museum and in the Museum of Practical 

 Geology ; and those gentlemen whose collections can best illustrate the work in hand 

 have obligingly opened their museums for my use and reference. My warmest thanks 

 are due to Prof. John Phillips, M.A., D.C.L., &c, and Mr. C. Spence Bate, F.R.S., &c. } 

 who, since the meeting of the British Association at Bath in 1864, have willingly aided 

 me in my researches in the British Fossil Crustacea. 



All assistance received will, I trust, be found duly acknowledged in its proper place. 



The present part forms only the first chapter of the history of the Merostomata, but it 

 has been considered desirable to issue this instalment on account of the number of plates 

 needed to illustrate the entire group, and the consequent delay caused by their pre- 

 paration. 



CLASSIFICATION OF THE MEROSTOMATA. 1 



I have experienced considerable difficulty in proposing a classification for this remark- 

 able group that may appear to differ to any extent from the conclusions of the eminent 

 zoologists who have preceded me in this work ; but Laving the advantage not only of 

 being able to consult and compare their published labours, but also of examining 

 numerous specimens in a far better state of preservation than any hitherto examined 

 or described in this country, I venture to hope that the following arrangement — with such 

 modifications as may be deemed needful during the publication of the remaining parts 

 of this Monograph — will be found to accord, not only with the general and detailed 

 structure of the group and their family relationships, but also as an appropriately framed 

 order of the great Crustacean class. 



1 This name (derived from fjrjpos, a thigh, and aro/xa, a mouth) was proposed by Dr. J. D. Dana in 

 his great work on the Crustacea (1852) already quoted, but is adopted here for a much larger group than 

 was contemplated by him. I prefer to enlarge a group proposed by so eminent a carcinologist, to the 

 alternative of introducing a fresh name or the adoption of one which, though older, is inappropriate, 

 having been founded upon an incorrect view of the structure of the fossil forms it included. (See p. 24, 

 paragraphs 28 and 33.) 



