Brackish-water Foraminifera. 289 
Lrochammina inflata, Montagu, sp. 
Nautilus inflatus, Montagu (1808), Suppl. Testacea Britannica, p. 81, 
pl. 18. fig. 3. 
Rotalina inflata, Williamson (1858), Rec. For. Gt. Brit. p. 50, pl. 4. figs. 
93, 94. 
This species has been carefully studied by Messrs. Parker 
and Jones from specimens washed out of the clay which un- 
derlies the peat in the Fen district near Peterborough. The 
organic remains contained in this deposit can scarcely be re- 
fen area and the open sea, and the fen-waters have become in 
consequence less saline, the present species, amongst others, 
as grown correspondingly less common, and its distribution 
limited to a few localities most favourable to its habit. 
Trochammina inflata is alike variable in its external con- 
tour and appearance and its choice of a habitat. The speci- 
mens originally described by Col. Montagu were from the 
evonshire coast, Prof. Williamson’s from Mr. Barlee’s and 
Mr. Jeffreys’s dredgings at various points around the British 
Isles ; but whilst the species is extremely rare in these dredged 
sands, it is one of those most commonly met with in the mu 
of shallow lagoons. > dd cs 
The deep-water (marine) specimens in our possession differ 
somewhat from the brackish type; they are smaller, thicker 
In proportion, have fewer chambers in each whorl, and show 
deep constrictions at the septa, especially in the under surface. 
o riei with these characters were obtained from depths of 
y fathoms and upwards at two or three points. on the west 
coast of Scotland, We have no record of its occurrence in 
the coralline or the laminarian zone, though it can scarcely be 
tak to cease entirely in intermediate depths. 
rofessor Williamson’s es (loc. 
h 
posite direction to the deep-water form just alluded to, and 
presenting about equal morphological affinity to Trochammina 
inflata and Lituola canariensis. A recent examination of a 
very large number of Lituoline Foraminifera from various lo- 
calities and depths of water on the western shores of Scotland 
afforded the clearest evidence that no truly specific, still less 
generie, distinction could be drawn between Valvulina (V. co- 
Ann. & Mag. N. Hist. Ser. 4. Vol. vi. 19 
