REVIEWS. 
89 
forming a rude contrast to the accuracy observed in others. As we are 
obliged to trust for the identification of Mr. Walker’s species solely to his de¬ 
scriptions, we hope that this criticism will not appear unfair to the respected 
author. Where the species are determined with precision, his descriptions are 
of a very different sort from those given where the discrimination of the species 
is ambiguous and obscure; in which case they degenerate into such insig¬ 
nificant phrases, even where the species of the genus are easy to distin¬ 
guish—take, for instance, the genus Chrysotoxum —or confound the charac¬ 
ters of sex and species (as in Paragus) to such a degree, that we are led 
to question the author’s acquaintance with the genuine species. These 
doubts affect a considerable portion of the family Syrphidce ; in par¬ 
ticular, of the genera Chrysotoxum , Paragus , Pipiza , Chrysogaster , but, 
above all, Cheilosia , in which there are not above two or three species 
about which we feel quite satisfied. The species of Musca , Tachina , and An- 
thomyia , also, are liable to many critical doubts, as Mr. Walker’s descrip¬ 
tions do not always suit the species which the names indicate. 
The principles of nomenclature which Mr. Walker has followed in the 
case of species previously described under various names are so just that 
it would scarcely have been necessary to single them out for approbation, 
were it not that they are so often violated by other writers, and unfortu¬ 
nately often for reasons the most trivial. In particular, we are glad to see 
many unobjectionable names of old date restored, which had been generally 
overlooked or forgotten of late. In the great majority of these instances 
his example is likely to be followed, as the application of the ancient names 
is self-evident. In one or two instances sundry doubts might be raised, 
and there it would probably have been more judicious to have retained the 
current names, about which there can be no question. Another merit of 
the same sort is that he has identified so many of the species described by 
British authors with those known on the Continent. The study of the 
synonyms has gained not a little, by this object having been kept so 
steadily in view, particularly in the Addenda to the last volume. It is only 
to be regretted that Mr. Walker has not referred more specifically to his own 
paper on the Sepsides , which has proved the source of many difficulties. 
His plan of a more particular reference to the earliest description, with the 
date, is to be recommended to imitation; the year, however, in several 
cases, requires to be corrected, particularly for the Linnean species, many 
of which ought to date back from the tenth edition of the Systema 
Naturae. Mr. Walker,, as Meigen had done before him, has also com¬ 
pletely ignored the ~ 
Eutomologiae, in which so many of the species 
