OUR BOOK SHELF. 223 
class are very diversely adorned by nature, their markings being 
very varied and generally characteristic for certain groups. 
A good monograph of this genus by Professor H. L. Smith 
may be found in “The Lens,” and this observer seems to have 
been the first who noticed the structure of the Amphora frustules. 
The ‘ Atlas of Diatoms” by Ald. Schmidt contains a large number 
of beautiful and more recently discovered species. 
The late Dr. Gregory in his work on the diatoms of the Clyde 
had previously described and figured many new marine species. 
Since then M. Grunow, M. Cleve, and various other naturalists 
have considerably increased the list. 
Habirshaw’s valuable catalogue of diatoms will furnish a com- 
plete list of the numerous species of Amphore, described and 
figured by all authors up to a recent date, with an index of the 
page of text in these works and the number of the plates and 
figures which bear upon it. The reader who is desirous of entering 
more deeply into the study of this interesting class is referred to 
the works of these able specialists, 
OUR BOOK SHELF. 
PROCEEDINGS of the Liverpool Naturalist Field Club, 1881. 
This is a small brochure of 88 pages, containing the President’s 
Address, resumé of excursions and evening meetings, with a list of 
the most interesting plants zo¢iced during the excursions in 1880, 
while last and not least is appended a list of books useful in the 
study of Natural History, and their prices and publishers. There 
is one omission, however, a publisher’s name should always be 
attached to these “ Proceedings,” so that the outside public may 
be able to procure them easily if it wishes. 
The President’s Address is full of interest ; it is entitled ANIMAL 
DEFENCES, INVERTEBRATE ANIMALS, and he proceeds to show 
that the whole economy and morphology of animals and their prey, 
“from a flea to a whale,” has been modified through the necessity 
of obtaining suitable food and protection. The volume is illus- 
trated: we find cuts of Difiugia carinata, sting-thread of Aydra 
vulgaris, the locust, Coreus bicolor, Diactor bilineatus, and a very 
fairly executed plate of Pentacrinus Mulleri. 
THE Microscope in its relation to Medicine and Pharmacy, 
Vol. L, No. 3, August, 1881. Ann Arbour, Michigan, 
This is a bi-monthly American Magazine, and we scarcely have 
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