NOTES AND CORRESPONDENCE. 
A New Difflugia—I have lately met with an undescribed 
species of Difflugia ; at least, I cannot find it either mentioned 
or figured in any published account of this genus. There can 
be no doubt that it is a distinct and and peculiar species. 
The carapace, instead of being more or less spherical, globose, 
or pyriform, is almost flat and triangular, one of its apices 
being truncated to form an orifice for the emission of the 
pseudopodia. It is so remarkably transparent that the 
animal is seen, as through a glass case, freely suspended in 
the interior, and its surface is covered with markings of almost 
mathematical regularity. 
I at first considered that this carapace was constructed of 
very minute pieces of pure diaphanous silica cemented to- 
