304 Mr. Henry B. Brady on 
figs. 90-92) represent excellently the typical Rotalia Beccarii 
as it ordinarily occurs both under marine and brackish, condi- 
tions. In some localities much affected by the influx of fresh 
water we have found a large proportion of the specimens as- 
suming somewhat modified characters. The peculiarities of 
these brackish individuals are not of sufficient importance or 
sufficiently uniform to need even varietal separation as to name, 
ut they are nevertheless of considerable morphological interest. 
Their divergence from the type is chiefly with respect to the 
size and general contour of the test, its texture, and the fitting 
together of the chambers. Our Plate XII. figs. 8 a—c repre- 
sent a fair example, though many could have been chosen 
showing the peculiarities more strikingly. These shells are 
usually white and opaque rather than hyaline in texture; the 
spiral face is less convex than in the type, sometimes quite 
at, the inferior side having a corresponding increase of con- 
vexity. The septation is much obscured, often scarcely dis- 
cernible on the spiral face beyond the last-formed circlet of 
chambers, though more frequently, as in fig. 8 a, the division 
may be traced through a second turn of the spire. The septa 
are radial rather than, as in the type, very oblique. The dia- 
meter seldom exceeds 4l, of an inch and is commonly less, 
whilst that of the type is from 4'; to = inch. There is often an. 
angular appearance about the periphery of the brackish variety 
that is not easily conveyed in a drawing, but which, neverthe- 
less, gives to the specimens a somewhat peculiar aspect. 
Rotalia Beccarit is one of the most widely distributed of all 
the brackish Rhizopoda, although the relative number of indi- 
viduals is not nearly so large as those of the genera Polysto- 
mella and Nonionina, The particulars noted in the Table 
refer to the distribution of the typical form ; the brackish modi- 
fication of the type above described occurs in the river Bure 
and in the Tyne (Jarrow Slake), and is the commoner of the 
two in the estuaries of the Blyth and Exe. 
Tinoporus levis, Parker & Jones, sp. 
Orbitolina levis, Parker & Jones (1860), Ann. & Mag. Nat. Hist. ser, 3. 
vol. vi. p. 33, no. 7, : 
Only a single specimen of Tinoporus levis, and that a 
somewhat worn and obscure one, has been noticed in the course 
of these examinations. It was found in the Bo'ness gatherin 
(Frith of Forth), and is probably a dead shell accidentally 
carried in by the tide from deeper sea. Under these circum- 
stances it has been omitted from the catalogue, pending better 
evidence of its power of living in brackish water. 
