384 Bib liographical Notices. 
relative to the stratigraphy and paleontology of the Belgian Ter- 
tiary strata, more especially of the subdivisions of the Eocene 
period, the descriptions of which occupy the greater part of the 
paper (pp. 5-85). Besides copious lists of fossils of the different 
subdivisions, a table is given showing the synchronism of the Kocene 
strata of Belgium, France, and England. Four pages only are de- 
voted to the Oligocene and Pliocene; but these will be further 
illustrated and described by the authors and M. E. Vanden Broeck. 
With regard to the strata referable to the Oligocene, M. Rutot con- 
siders that the Bolderien, Upper and Lower Rupelien, and Upper Ton- 
grien systems of Dumont correspond to the Middle Oligocene of the 
Germans, to the Fontainebleau sands of France, and to the Osborne, 
Bembridge, and perhaps the Hempstead series of England. The 
Lower Oligocene will include the Lower Tongrien of Dumont, the 
upper part of the Paris gypsum, and the Headon series of the Isle 
of Wight. 
Monograph of the British Aphides. By Grorcr Bownter Bucxton. 
3 vols. 8vo. London: Ray Society, 1876-1881. 
Somz months ago we noticed the completion of Mr. G. 8. Brady’s 
treatise on the British non-parasitic Copepoda, published by the Ray 
Society. Another work, scarcely of less interest, has since been com- 
pleted under the auspices of the same valuable institution, namely 
Mr. Buckton’s ‘ Monograph of the British Aphides,’ which has been 
in progress since the year 1876. This book may perhaps be re- 
garded as hardly taking so high a position in zoological literature as 
that above mentioned, seeing that, although denominated a Mono- 
graph, it does not profess to include all the British species of the 
group of which it treats ; but, as dealing with a group of animals 
representatives of which are almost constantly under our eyes 
wherever we go, and which present some of the most extraordinary 
developmental phenomena that can be met with in the animal 
kingdom, it may fairly be regarded as appealing to a wider circle of 
students than Mr. Brady’s complete and elaborate essay. Moreover, 
so far as we can see, the number of British types omitted cannot 
be very great, and we have the further advantage that the whole 
of the species are described from the author’s personal obser- 
vations. 
Mr. Buckton opens his first volume with a general introductory 
chapter on the Aphides, describing the structural peculiarities of 
the group, both external and internal, the remarkable phenomena 
of their development as understood five years ago, and certain other 
points in the general natural history of the family, and also giving 
a brief sketch of the bibliographical history of the group. This 
introduction is followed by the systematic descriptions of the species 
and genera, in which, as regards classification, the author follows 
generally in the steps of his predecessors. His descriptions 
