1896.] Zoology. 943 
ZOOLOGY. 
Fishes in isolated pools.—The occurrence of fishes in pools 
which have no communication with running streams or large bodies of 
water has been often noticed, and the explanation of their origin and 
persistence in such places is in some cases not satisfactory. 
In collecting during this month (September) in Camden county, 
New Jersey, I made the following observations. I fished near Winslow, 
a pool of about twenty-five feet in diameter, and two feet in depth, with 
a muddy bottom and a few Nympheas growing init. It is distant 
about a quarter of a mile from an insignificant ditch with a little run- 
ning water, and is surrounded by higher and sandy ground, offering no 
possible communication with the ditch. A half mile distant and still 
more inaccessible is a running stream. From this pool I caught large 
numbers of the following fishes. Umbra pygmea, Apomotis obesus and 
Acantharchus pomotis. The Acantharchi were small, while the others 
were fully grown. 
A quarter of a mile distant from this pool, and at an equal distance 
from the ditch above mentioned, and not connected with it by any de- 
pression of the surface, is another pool of about thirty feet in diameter. 
The water reaches a depth of three feet in a limited portion of it, and 
Nympheeas are more numerous, together with Utricularia, ete. Here 
I obtained the following fishes in considerable numbers. Umbra pygmea, 
Amiurus prosthistius, Esox vermiculatus, Aphododerus sayanus, Apom- 
otis obesus, Mesogonistius chaetodon, Acantharchus pomotis. Many of 
these were fully grown. The turtle Chrysemys picta was also abun- 
dant. 
The mud in the first mentioned pool was light colored, and all the 
fishes were remarkable for the extreme paleness of their tints. The 
second pool is situated in better soil and its mud contains much decom- 
posing vegetable matter, and is consequently black. The fishes were 
all deeply pigmented, including the three species found in the other 
pool, from which they could be distinguished at a glance. The smaller 
pool was said to have been dried up during the past summer. 
Seven additional specimens of the Amiurus prosthistius Cope enable 
me to verify the characters already given (Proceeds. Acad. Nat. Sci., 
Philada., 1883, 133), from an examination of four from the Batstow 
River, New Jersey. In five of the new specimens where I counted the 
anal rays, they number 26. Prof. Jordan has recently attempted to 
