Foraminifera of the Gault of Folkestone. By F. Chapman. 3 
thickened. The test of C. subalata , moreover, is more inflated in the 
umbilical area. C. circumcidanea was found in the Gault of Mont- 
cley and l’Aube (Berthelin). 
At Folkestone the species occurs in zone i., specimen b, frequent; 
zone ii,, specimen b, very rare ; zone iii., rare ; zone ix., very rare ; 
zone x., very rare; zone xi., 55 ft. from the top, very rare; 45 ft., 
very rare ; 35 ft., very rare. 
Cristellaria subalata Reuss, plate I. fig. 3 a , b. 
C. subalata Reuss, 1854, Denkschr. k. Ak. Wiss. Wien, vol. vii. 
p. 68, plate xxv. fig. 13. C. subalata Reuss, 1862, Sitzungsb. d. k. 
Ak. Wiss. Wien, vol. xlvi. p. 76, plate viii. fig. 10 ; plate ix. fig. 1. 
C. megalopolitana Reuss, 1855, Zeitschr. d. geol. Gesellsch., vol. vii. 
p. 267, plate ix. fig. 5. C. megalopolitana Sherborn and Chapman, 
1886, Journ. Roy. Micr. Soc., ser. 2, vol. vi. p. 755, plate XY. 
fig. 30 a, b. 
This is a neat little Cristellarian in the Gault series ; the examples 
from other formations are not quite so circular in outline nor so swollen, 
although in their main characters agreeing very closely. 
Reuss’ specimens from the Neocomian of Germany apparently 
had no umbilical protuberance, whilst the specimens from Gosau 
(Upper Cretaceous) resemble those from the Folkestone Gault in 
possessing an umbilical boss. 
This form has been recorded from the Speeton Clay and the 
Minimus- clay of North Germany (Reuss) ; from the Gault of 
Montcley and l’Aube, France (Berthelin) ; from the Gault of Folke- 
stone (Reuss and Rupert Jones) ; from the Cretaceous Marls of 
Gosau, Eastern Alps (Reuss) ; and from the Eocene, London Clay 
(Sherborn and Chapman). 
At Folkestone C. subalata was found in zone i., specimen b, very 
rare ; zone ii., specimen e, very rare ; zone ix., very rare. 
Cristellaria secans Reuss var. angulosa nov., plate T. fig. 4 a , b. 
The type species * of the above variety belongs to the thick-keeled 
group of Cristellarians, and is further distinguished by its strong and 
prominent sutural ribs. 
The variety here figured is characterised by the flattening of 
the peripheral edge between the termini of the sutural costae, thus 
imparting a subangulate appearance to the test. Diam. 1/35 in. ; 
thickness 1/64 in. 
A somewhat analogous form was figured by Reuss as C. sub- 
angulataf but this belongs rather to the C. rotulatu type ; and with 
lineate sutures instead of strong riblets, as in C. secans. A similar 
* Sitzungsb. d. k. Ak. Wiss. Wien, xl. (1860) p. 214, pi. ix. fig. 7 a, b. 
t Op. cit., xlvi. (1862) p. 74, pi. viii. fig. 7 a, b ; Denkschr. k. Ak. Wiss. Wien, 
xxv. (1865) p. 144, pi. iii. fig. 17. 
B 2 
