iv FORAMINIFERA OF THE CRAG. 
individuals and variety of forms, but composed of dwarfs in contrast with those of Sutton, 
except in the case of some of those that inhabit shallow water, as Rotalia Beccarii and 
Polystomella crispa, and even these are but feeble. Hence we may suppose that the 
Foraminiferal deposit at Sutton was formed either in deeper or in warmer water than 
other portions of the Crag were. Some of our sources of these less luxuriant growths are 
specimens of Crag full of Cyprina and Cardita; and as the former shell lives in the 
British seas, at from 5 to 80 fathoms—a depth similar to that affected by the Atlantic 
and Mediterranean groups of Foraminifera above alluded to, we must suppose that some 
deteriorating influence, either cold currents, floating ice, or cold climate, was at work 
locally, at least, in the Crag sea, excepting possibly the Sutton area. 
Similar conditions are pomted out by the Bivalved Entomostraca of the Crag, the 
distribution of which will be treated of in an Appendix to this Monograph. 
A group of Foraminifera, doubtlessly imperfect as a fauna, from a specimen of Crag 
with Ostrea, consisted of Polymorphina Thouini, P. gutta, Textularia agglutinans, 
T. trochus, and Nonionina scapha, all of middling size, and rather common. ‘These also 
indicate water of moderate depth in a temperate climate. From the shelly Crag of 
Aldborough we have Polymorphina lactea (small and rare), Rotalia Beccarii (small and 
rare), Polystomella striatopunctata (middle-sized and common), and Zruncatulina lobatula 
(very small, and rather common). ‘These belong, probably, to the beds overlying the 
Lower Crag, and indicate shallow water. A similar group occurs at Bramerton and 
Thorpe, in the “ Norwich” or “ Fluvio-marine Crag,” and also in the Uppermost Crag at 
Chillesford, which is continued, according to Mr. Searles Wood, jun., over the “ Norwich 
Crag” at Aldborough, Bramerton, and Thorpe. 
We have also to notice that among the Foraminifera of the Crag there are some that 
have been, in all probability, derived from older Tertiary beds; such are A/veolina, sp., 
and Orbitoides Fawjasii. Amphistegina vulgaris, Nummulina planulata, and Operculina com- 
planata also attract attention as possibly having been washed out from Miocene and Hocene 
strata. None of these are common; and somewhat imperfect water-worn specimens are 
all the evidence we have of the two first-named. 
Of the Foraminifera of the Upper or Red Crag, we have but a poor supply ; indeed, 
it is not easy to determine in every instance whether we have a zative or a derived fossil 
in a specimen from the Red Crag, as with this deposit are mixed fossils from the Lower 
or White Crag, and even from older Tertiary beds. (See Mr. S. V. Wood’s memoir on 
this subject, ‘ Quart. Journ. Geol. Soc.,’ vol. xv, p. 32, 1858.) 
The Foraminifera of the Red Crag indicate a rather shallow sea-zone ; they comprise 
a few common species of AMiliola, Polymorphina, Teatularia, Truncatulina, Rotalia, Cal- 
carina, Polystomella, and Nonionina ; not abundant as individuals, nor of large size ; and 
are such as live at present in the British Seas, with the exception of Calcarina. 
The Mammaliferous or Norwich Crag (Thorpe, Southwold, and Bramerton) yields a 
Rhizopodal fauna somewhat similar to that of the Red Crag. 
