7 
white chalk, and formed not only by the same genera of Forami- 
nifera, but even by the same species which Croydon microscopists 
have washed out of their chalk ; associated with these, are silicious 
parts of sponges, diatoms, &c., which hereafter may become aggre- 
gated together and form bands of flint, as similar organisms in 
the old cretaceous sea have partly contributed to produce the flint 
nodules so characteristic of the upper chalk. 
The following species of Foraminifera, according to Professor 
T: R. Jones, are found both living and in the Cretaceous rocks :— 
J.—AreEnacrous FORAMINIFERA. 
LITUOLIDA— 
Webbina rugosa, D’ Orb. 
TI.—Prrrorate, oR Hysuine ForAMINIFERA. 
LAGENIDA— TEXTULARIDA— 
Lagena globosa, JJont. Textularia globulosa, Ehr. 
3,  sulcata, W. & J. a gibbosa, D’ Orb. 
Glandulina levigata, D’ Orb. Ss agelutinans, D’Orb. 
_ Lingulina carinata, D’Orb. as trochus, D’ Orb. 
Nodosaria radicula, Linn. a: turris, D’ Orb. 
. raphanus, Linn. Vulvulina pennatula, Batsch. 
ss acicula, Lam. Spiroplecta biformis, P. & Jones. 
s glabra, D’Orb. Verneuilina triquetra, v. JZ. 
= ovicula, D’ Orb. 3 pygmea, Hyger. 
; Dentalina communis, D’Orbd. 
9 pauperata, D’ Orb. GLOBIGERINIDA— 
Cristellaria Italica, Defrance. arte 5 P 
ey triangularis, D'Ord. Globigerina bulloides, D Orb. 
a eultrata, Montf. 2 pelagica, D'Orb. 
se rotulata, Lam. Rotalia Becearii, Lin. 
pt crepidula, F. & M. ;,  umbilicata, D’Orb. 
Planorbulina farcta, 7. & I. var. 
PoLYMORPHINIDA— A Haidingeri, D’Orb. 
Polymorphina lactea, W. & J. ” Ungeriana, D’Orb. 
oy communis, D’Orb. 6 ammonoides, fezss. 
as compressa, D’ Orb. ”» globulosa, Ehr. 
;. Orbignii. i ariminensis, D' Orb. 
“a Sb lobatula, 17. & J. 
Pulvinulina crassa, D’ Ord. 
Bolivina punctata, D’Orb. a Menardi, D’Orb. 
Virgulina Schreibersii, D’Orb. Af Micheliana, D’Ord. 
= Hemprichii, D' Orb. Calearina Spengleri, Gime/. 
‘‘ With the Rotalinz, as with Globigerina, the chief distinction 
between the Cretaceous and existing groups is in the progressively 
increased number of modifications, and among them the incoming 
of important variations, though few of them are of generic, or 
even of specific value—a distinction strong enough, when supported 
by other known geological and paleontological considerations, to 
mark the impropriety of calling the Atlantic ooze ‘ Chalk,” except 
in the sense of a calcareous rock of marine organic origin.” * 
* “Cretaceous Rotaline,” Jones and Parker, Quart. Journ. Geol. Soc., May, 1875. 
