NIPHARGUS FONTANUS. 
321 
to the Hope Collection at Oxford) in a similar well about 
two hundred years old at Corsham in Wiltshire, as above- 
mentioned. Mr. Lubbock has also taken it in a well at 
High Elms in Kent. 
Through the kindness of Mr. Hogan, who sent us 
living specimens, we were enabled to watch it alive for 
many weeks. There appeared little in the habits of 
this creature that distinguished it from the common 
Gammarus of our fresh-water streams, for even its 
desire to seek the darkness (and Mr. Hogan informs 
us that it soon dies if exposed to the light) is but an 
exaggeration of the habits of these Crustacea to hide 
themselves beneath rocks, stones, and weed. 
We observed, when watching the animal very closely, 
that the strong spines, which define the limits of the 
palm on the first two pairs of hands, are moveable. 
The colour of the animal is of a milky hue, but not 
quite white. The eyes are brimstone yellow, small, and 
irregularly formed. 
If we are correct in following Schiodte in assuming 
that the difference of length in the posterior caudal 
appendages of certain specimens indicate sexual dis- 
tinction, it is at least a curious circumstance that the 
long- tailed form was not found associated at Corsham 
and Ringwood ; the males, if such they were, being 
found at Corsham in Wiltshire,* and the females taken 
at Ringwood in Hampshire. 
In the “ Catalogue of Amphipoda of the British 
Museum,” we have stated that the males also differ 
from the females in having the second pair of hands less 
tapering and graceful; but we find that it is the females 
* Among the specimens presented by Mr. Mullins to the Hope Collection, 
is a female with the terminal segments as represented in our figure u z. 
Y 
