iv rORAMINIFERA 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 

 Folysioviella crisjja, 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 Cardifa ; 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 pointed 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 Thotiini, P. gutta, Textularia agglutbians, 

 T. trochus, and Nonionina scapJia, 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), Eotalia Beccarii (small and 

 rare), PolystomeUa striatopunctata (middle-sized and common), and Truncatulina lohatula 

 (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 Alveolina, sp., 

 and Orbitoides Faujasii. Amphistegina vulgaris, Nammulina planulata, and Operculina com- 

 pla}iaia also attract attention as possibly having been washed out from Miocene and Eocene 

 strata. None of these are common ; and somewhat imperfect water-worn specimens are 

 all the evidence we have of the two tirst-named. 



Of the F'oraminifera 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 native or a derived fossil 

 in a specimen from the Eed 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 Miliola, Polymorphina, Textularia, Truncatulina, Rotalia, Cat- 

 carina, PolystomeUa, 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. 



