Preface vii. 



of the descriptions embody, verbatim, entire paragraphs of 

 Mr. Theobald's work, but the necessities of condensation 

 have so frequently involved alterations of verbiage and 

 sequence, that it has been found impracticable to indicate 

 these by inverted commas, and I trust that this acknow- 

 ledgment will suffice to show how fully I realise my in- 

 debtedness to the Monograph for much of the matter of 

 the following pages ; and I desire here to express my deep 

 appreciation of the courtesy and kindness with which my 

 work has been in every way facilitated by Professor Kay 

 Lankester and the other authorities of the Museum, and 

 in especial to Mr. Theobald, but for whose exceptional 

 generosity in placing at my disposal early proof sheets, 

 and in personally helping me in every possible way, the 

 appearance of this edition nmst necessarily have been 

 delayed for several additional months. 



There are some hundreds of drawings in the new plates 

 and figures which, with a few exceptions, have been drawn 

 by the writer himself from camera lucida outlines, and 

 it is needless to say that all these changes have taken 

 much time, but were inevitable, if the new issue was not 

 to be rendered almost immediately obsolete by the appear- 

 ance of the Monograph. 



To facilitate comparison of neighbouring species, the 

 figures illustrating them have been, as far as possible, 

 grouped into plates, instead of interspersing them in the 

 text. 



As to the question of which of the older names are mere 

 redescriptions of one and the same species — the synonymy of 

 the group — I have followed implicitly the new Monograph, 

 and it must be understood that, in relegating any given 

 name to this category, I merely reproduce, and desire to 

 imply no personal opinion as to the justness or otherwise 

 of the conclusions involved. 



Saving only, then, those of some few species, of which 

 no examples have come to hand, all the descriptions in 

 the present edition are drawn up from actual observation, 

 and no attempt has been made to reproduce the original 

 descriptions. 



