196 THE AMERICAN MONTHLY [July 
stagnant swamps all over the world are likely to be found 
the characteristic rotifers of stagnant water, with little 
regard to the country ; in clear lake-water, everywhere, 
the characteristic limnetic Rotifera may be obtained ; in 
sphagnum swamps the Sphagnum or moss Rotifera. Va- 
riation in the rotifer fauna of different countries is prob- 
ably due to variation in the conditions of existence in the 
waters of those countries, not to any difficulty in passing 
from one region to another. In the introduction the au- 
thor gives a word of warning agaiust the naming of spe- 
cies by those persons who, through want of experience or 
knowledge of what is known, are not in a position to dif- 
ferentiate new forms. Such work he describes as a posi- 
tive injury to science and a nuisance to all careful scien- 
tific students. It is to be hoped that everyone wishing to 
describe a new species of rotifer, will learn by heart and 
inwardly digest this sentence. In the very next para- 
graph the journal refers to a contribation on this subject 
in the “Trans, New Zealand Inst.” by Mr, F. W. Hilgen- 
dorf, which comes under the above strictures. The author 
succeeded in finding sixteen species of rotifers, twelve of 
which he describes as new. Half of these can at once be 
recognized as old acquaintances, and the other half are of 
no value, and scarcely to be identified as rotifers. The fig- 
ures of the four plates, remarks the writer of the notice, 
bear about the same relation to rotifers as the wooden 
blocks in a child’s Noah’s Ark do to the animals they pre- 
tend to represent. | 
ScaLkEs oF FisHES.—The scales of fishes are objects of 
much interest to the geologist and zoologist as well as to 
the microscopist, and are therefore at all times an inter- 
esting study. They are important features in classifica- 
tion, throwing light on the conditions of the waters in- 
habited by their possessors, and contribute not only to the 
understanding of the conditions and life of the present 
seas, but add their quota to the sum of our knowledge of 
