PREFACE. Vil 
of our students the best assistance I could recommend for 
their studies in this direction. In fulfilment of it I ap- 
plied to Professor Van pir Horven for his permission 
to translate his Work, in which I found all that could 
be required. He had the kindness not only to grant this 
permission, but also to enrich the English translation with 
numerous references to works too recent for notice in his 
own second edition. It is to be much regretted that his 
other engagements did not allow him, as I requested, 
to weave the new matter in his own terse and pleasing 
style into his introductions to the classes and elsewhere. 
Consequently such additions, in this respect, as are in- 
cluded within square brackets are mine. 
The study of Zoology is now in such general favour 
with cultivated persons in this country, that I believe the 
present work, from its scientific value and the interest of 
its historical and other notices, as well as from the con- 
tinuous references to the works of the original discoverers, 
will secure for itself, beyond the walls of Universities, a 
reception not unworthy of its Author’s great name. 
Wee. 
CAMBRIDGE, July 1, 1856. 
