PREFACE. 
VII 
years and by many persons, but having never been fully revised by hint 
have an unequal value. It was impossible, from their multitude and 
the vast labor involved, to subject them to a critical examination, so 
that while I have given them as found, it is only justice to the source 
from which they came to make this explanation. 
Through the intervention of Mr. E. 0. Rye, of London, who himself sent 
me various memoranda of omissions from previous lists, I received a man- 
uscript catalogue of genera proposed in diptera, including their variations 
in orthography, prepared and forwarded to me by Mr. G. H. Verrall, of 
Newmarket ; the number of these, reaching several thousands,* would 
surprise even a specialist in that group. Free use has been made of this 
list so generously offered, and every name not previously recorded will 
be found entered in the body of the Supplemental List. The list did 
not contain complete references, but, in general, only indications of 
author and date; fuller details, however, were in some instances fur- 
nished by Mr. Yerrall on application. 
Of other lists supplied by specialists in their own departments, I must 
express my very great obligations to Mr. J. Bigot, of Paris, who kindly 
sent me detailed references to three hundred and eighty -five genera of 
diptera, referred to neither by Agassiz nor Marschall, bringing the list 
down to May, 1879. To Oapt. W. H. Dali, of the United States Coast 
Survey, I am indebted for a vast number of memoranda of various kinds 
upon mollusca, including a complete list of his own genera, besides 
many corrections made upon the proofs of my work submitted to him ^ 
these are all made with his usual care and precision. The entries re- 
ceived from Mr. Waterhouse, of the British Museum, to which allusion 
has been made, have an especial value, since nearly all the references 
obtained by him from secondary sources have received his careful veri- 
fication, and the list was made up of omissions from previous records ; 
his list and Mr. DalFs have been, after those obtained from Mr. Agassiz 
and Mr. Yerrall, perhaps the most extensive of all. I have received 
also the very welcome and generous assistance of Mr. W. H. Dalton, of 
H. M. Geological Survey, London, whose special work on the Geological 
Record f enabled him to send me an extensive list of overlooked genera 
of fossil animals, which were the more desirable from their having been 
so generally neglected since Agassiz’s time. Similar aid was received 
from Mr. W. F. Kirby, of the British Museum, who sent me a long array 
of names in lepidoptera, mostly of recent years, which his labors on the 
* In February, 1882, Mr. Verrall wrote me that this list, which when sent to me con- 
tained about 4,400 names, of which he had seen the original references* to all except 
about 290, now contained 4,900 names; of these he considers fully one-third as only- 
misprints or misspellings, which had been collected for index purposes, erroneous, 
forms being frequently misleading and troublesome. 
t The geological record for 1874 [-1877]. An account of works on geology, miner- 
alogy, and palaeontology published during the year. Edited by William Whitaker. 
8°. London, 4 vols., 1875-1880. The last two volumes add to the title: With sup- 
plements for 1874-1875 [1874-1876]. 
