464 EL N. eaverson—Foraminifera of the Hartwell Clay. 
Specimens of C. dalica from the Hartwell Clay resemble those 
from the Gault of Folkestone in having sharp edges and a distinct 
keel. Some elongated specimens approach C. bononiensis Berth., 
but preserve the spiral commencement. Ranging from the Lias 
upwards, the species has already been recorded from the Hartwell 
Clay (Chapman). It also occurs in the Gault of Folkestone 
(Chapman), and the Aptian of Surrey (Chapman). At the present 
day it is found in shallow water at depths varying from 90 fathoms 
in the Mediterranean to 725 fathoms in the North Atlantic (Brady), 
Localities: Hartwell (a.); Aylesbury (c.); Bierton (c.); Long 
Crendon (a.); Whitchurch (f.); Wheatley and Shotover Hill, 
bed 2 (a.), bed 1 (c.). 
Cristellarva sulcifera Reuss. 
Cristellaria sulcifera Reuss 1862; Sitz. d. Akad. Wiss. Wien, vol. xlvi, pp. 74> 
93, pl. viii, fig. 8. 
C. sulcifera Chapman, 1894; Journ. Roy. Micr. Soc., p. 650, pl. x, fig. 2. | 
This form often approaches C. ztalica, with which it appears to 
be connected by transition-forms, but typical specimens are easily 
distinguished by the grooved sutural lines. C. sulcifera has been 
recorded from the Minimus-clay of Germany (Reuss), Aptian of 
Surrey, Gault of Folkestone, and the Hartweil Clay (Chapman). 
Localities : Hartwell (f.); Wheatley, bed 2 (r.). 
Cristellaria navicula d’Orb. 
Cristellaria navicula d’Orbigny, 1840; MZém. Soc. Géol. Fr., ser. 1, vol. iv, 
p. 27, pl. ii, figs. 19, 20. 
C. navicula Reuss, 1845; Verstein. bohm. Kreidef., pt. i, p. 34, pl. xii, fig. 27. 
CO. navicula Chapman, 1894; Journ. Roy. Micr. Soc., p. 650, pl. x, fig. 1. 
Recorded from the Hartwell Clay (Chapman), C. navicula occurs 
in the Gault of Monteley (Berthelin), the Gault of Folkestone 
(Chapman), and many Upper Cretaceous faunas. 
Localities : Hartwell (f.) ; Long Crendon (v.r.) ; Wheatley, bed 2 
a: 
Cristellaria convergens Bornemann. 
Cristellaria convergens Bornemann, 1855; Zecitschr. deutsch. geol. Gesellsch., 
vol. vii, p. 327, pl. xiii, figs. 16, 17. 
CO. convergens Brady, 1884; Chall. Rep., vol. ix, p. 546, pl. Ixix, figs. 6, 7. 
O. convergens Chapman, 1896; Journ. Roy. Micr. Soc., p. 4, pl. i, fig. 6 
Chapman has already noted this form from Hartwell. It is also 
recorded from the Tertiary of Hermsdorf (Bornemann), the Gault 
of Folkestone (Chapman), and the Aptian of Surrey (Chapman). 
At the present day it is characteristically a deep-water form. 
Localities : Hartwell (f.) ; Aylesbury (v.r.) ; Long Crendon (f.). 
Cristellaria complanata Reuss. 
Oristellaria complanata Reuss, 1845; Verstein. bohm. Kreidef., pt. i, p. 33, 
pl. xiii, fig. 54. 
CO. complanata Reuss, 1862 ; Sitz. k. Akad. Wiss. Wien., vol. xlvi, p. 92, pl. xii, 
falter, 118% 
O. complanata Chapman, 1894; Journ. Roy. Micr. Soc., p. 653, pl. x, fig. 12. 
Originally described from the Planermergel of Bohemia, this 
