Brackish-water Foraminifera. 283 
of additional species, which may be regarded as “ semi- 
brackish” —in other words, such as will tolerate in a limited 
degree brackish conditions, whilst normally marine in their 
habit. The most conspicuous of these belong to the genera 
Lagena (of which almost every British variety occurs), Buli- 
mina, Bolivina, Discorbina, Truncatulina, and Patellina. 
Reference to the Table will extend the category, and show the 
particular forms which occur. 
. A third series would embrace the Fen localities, which, 
zoologically as well as geographically, stand by themselves, 
the fauna consisting, as already stated, of the species which 
have survived the gradual change in the surface-contour of 
that district. . 
Testaceous Rhizopoda of the lower types are often so perish- 
able in their nature that the investments of many are destroyed 
or their characters obliterated by the mere process of washing 
anc ing the muddy material in which they live. As most of 
the examinations were necessarily made on material so treated, 
there is little to offer with respect to the organisms stand- 
ing immediately lower in the scale; but as their relation to 
the Foraminifera is very intimate, a mere enumeration of those 
which have been noticed and the localities in which they were 
taken will tend to general completeness. This unfortunately 
cannot be extended beyond the Difflugie. Dr. Wallich's ex- 
cellent plate (Ann. & Mag. Nat. Hist. ser. 3. vol. xiii. pl. 16, 
arch 1864) will be a convenient ery E agp EC 
The typical Diflugia pyriformis of Carter (Ann. vol. xiii. 
pl. 1. "EN Jan. Cr fe Waihi. loc. cit. figs. 9, 10) is by far 
the commonest form. It was found in the Coquet, the Wans- 
