8 
Transactions of the Society. 
men a, rare ; zone ii., specimen b, rare ; zone iii., very common ; 
zone iv., common ; zone v., rare ; zone vi., very common ; zone vii., 
frequent ; zone viii., frequent: zone ix., common; zone x., common ; 
zone xi., 55 ft. from the top, very rare ; 50 ft., frequent ; 45 ft., 
frequent ; 40 ft., frequent ; 85 ft., common ; 30 ft., frequent ; 25 ft., 
common ; 20 ft., very common ; 12 ft., frequent; 6 ft., common. 
Cristellaria sternalis Berthelin, plate II. fig. 1 a, b. 
C. sternalis Berthelin, 1880, Mem. Soc. geol. France, ser. 3, 
yoI. i. No. 5, p. 54, plate iii. fig. 2 a, b. 
This form is perhaps more correctly to be regarded as a variety of 
G. cultrata, but since it bears some few distinct characters of its own, 
exhibited in all of the Gault specimens of this type, it may here 
he retained under the above name. 
The width of the test in G. sternalis is much greater than in 
typical specimens of G. cultrata , and the chambers are less numerous. 
The keel is always well developed, and the central boss very large. 
G. sternalis has been described from the Gault of Montcley, 
Wissant, and l’Aube (Berthelin). It occurs at Folkestone in zone i., 
specimen b, very rare ; zone ii., specimen b, very rare ; zone ii., 
specimen c, rare ; zone iii., very rare ; zone v., very rare ; zone vi., 
frequent ; zone viii., rare ; zone x., rare ; zone xi., 55 ft. from the 
top, rare ; 50 ft., rare ; 45 ft., very rare ; 35 ft., frequent ; 30 ft., 
very rare; 25 ft., very rare ; 12 ft., very rare; 6 ft., very rare. 
Gristellaria diademata Berthelin, plate II. fig. 2 a , b. 
C. diademata Berthelin, 1880, Mem. Soc. geol. France, ser. 3, 
vol. i. No. 5, p. 51, plate iii. figs. 4, 5, 12, and 13. 
The above name was given to the Gault form, which, although 
approximating to that of G. cassis (Fichtel and Moll) * in many 
particulars, yet differs essentially in having a more swollen test, and 
by the absence of the thickened and often beaded septal lines seen in 
typical recent examples of that species. 
The undulate keel-edge of G. diademata is always more or less 
irregular in its outline, apart from the fractures which a thin flange- 
like structure would be likely to sustain in a fossil-deposit laid down 
in moderately shallow water. 
G. diademata was described from the Gault of Montcley, Wissant, 
and l’Aube (Berthelin). 
At Folkestone it was found in zone i., specimen a, rare ; zone i.. 
specimen b, rare ; zone ii., specimen c, very rare ; zone iii., very rare ; 
zone v., very rare; zone vi., common; zone vii., rare; zone viii., 
rare ; zone ix., rare ; zone x., common ; zone xi., 55 ft. from the top, 
rare ; 50 ft., very rare ; 45 ft., very rare ; 40 ft., very rare ; 35 ft., 
rare; 30 ft., frequent; 25 ft., rare ; 20 ft., rare; 12 ft., rare. 
* Test. Micr., 1798, p. 95, pi. xvii. figs. a-l\ pi. xviii. figs. a-c. 
