652 
Transactions of the Society. 
it was found in the present series from Folkestone in zone ii., 
specimen a, very rare ; zone ii., specimen h, rare ; zone ii., specimen 5 , 
rare ; zone iii., very rare ; zone v., very rare ; zone ix., very rare ; 
zone xi., 55 It. from the top, very rare ; 40 ft., rare. 
Cristellaria tripleura Reuss, pi. X. fig. 6, a , h. 
Cristellaria tripleura Reuss. 1860, Sitzungsb. d. k. Ak. Wiss. 
Wien, vol. xl. p. 211, plate ix. fig. 5. C. tripleura Reuss, 1862, 
Sitzungsb. d. k. Ak. Wiss. Wien, vol. xlvi. p. 70. 
The examples of C. tripleura from the Gault of Folkestone are 
very characteristic. Reuss described the species from the Minimus- 
thon (the equivalent of the English Gault) of Westphalia. 
It was found at Folkestone in zone i., specimen h, very rare ; 
zone ii., specimen c, very rare. 
Cristellaria scitula Berthelin, plate X. fig. 7 a, h. 
Cristellaria scitula Berthelin, 1880, Mem. Soc. geol. France, 
ser. 3, vol. i. No. 5, p. 53, plate iii. fig. 3 a-c. 
This species was described by Berthelin from the Gault of 
Montcley. The test of C. scitula is more elongate and compressed 
at the sides than C. triangularis , and the spiral commencement is 
inconspicuous. 
C. scitula was found in the Folkestone Gault in zone xi., 6 ft. 
from the top, rare. 
Cristellaria latifrons , plate X. fig. 8 a, h. 
Cristellaria latifrons Brady, 1884, Chall. Rep., vol. ix. p. 544, 
plate lxviii. fig. 19 ; plate exiii. fig. 11 a, b. 
The above species was described by Dr. Brady from recent speci- 
mens found off the West Coast of New Zealand, at 275 fathoms; 
and off Culebra Island, West Indies, at 390 fathoms. 
The Gault specimen is fairly typical, although the latter chambers 
are not quite so erect as in the recent examples. 
The only specimen of C. latifrons from the Gault was found in 
zone x. 
Cristellaria Bononiensis Berthelin, plate X. fig. 9 a, b. 
Cristellaria Bononiensis Berthelin, 1880, Mem. Soc. geol. France, 
ser. 3, vol. i. No. 5, p. 55, plate iii. fig. 23 a-c. 
This species belongs to the type of C. Italica. It is a very con- 
stant form in the Gault, and was originally described by Berthelin 
from the Gault of Wissant and l’Aube. 
In the specimens from Folkestone it is difficult in most cases to 
make out the secondary costulate ornamentation of the ventral or 
front aspect, such as is figured by Berthelin, but the strong median 
costula is always present. 
