6 
Transactions of the Society. 
Only a few of the more important references to Cretaceous 
examples of the above species are here given, although the synonymy 
is very large. Some of the forms here retained as species distinct 
from G. rotulata are treated thus not because of any virtual specific 
differences, but since they have been already figured and described 
they may serve a useful purpose in elucidating the distribution of these 
minute fossils in the various horizons of the Gault. 
G. rotulata is well distributed through the various horizons of the 
Gault ; and it has been recorded from nearly all important fossiliferous 
deposits from the Lias upwards. For our present purpose it is only 
necessary to mention the occurrences of the above species in the 
strata immediately below and above the Gault. 
In this country it has been recorded from the Lower Greensand 
and the Gault of Meux’s well-boring (C. Moore) ; from the Speeton 
Clay of Fork shire and the Lower Greensand of Faringdon, Berkshire 
(Reuss) ; from the Lower Greensand of Surrey (Chapman) ; from the 
Gault of Folkestone (Reuss and Rupert Jones) ; from the Greensand 
of Warminster (Reuss) ; and from the Phosphatic beds of Cambridge 
(G. R. Vine). In France it was found in the Gault of Montcley, 
Wissant, and l’Aube (Berthelin). In North Germany it has been 
recorded from the Speeton Clay, the Minimus-o\.&y and the Flammen- 
mergel (Reuss). In Bohemia it was found in Cenomanian strata 
(Perner). This species has many records from the Chalk strata, and 
it is probably to be met with at all horizons. 
G. rotulata has also been recorded from the Red Chalk of Speeton 
by Messrs. Burrows, Sherborn, and Bailey ; one of the figures * given 
under the above name, however, appears to agree more- closely with 
the form G. rotulata var. 7nacrodiscus, referred to below. 
In the Folkestone Gault G. rotulata occurred as follows : — Zone i., 
spec, a , rare ; zone i., spec, h, rare ; zone ii., spec, a, rare ; zone ii, , 
spec, b, very rare; zone ii., spec, c, very rare; zone iii., frequent ; 
zone iv., common ; zone v., rare ; zone viii., rare ; zone x., very rare ; 
zone xi., 50 ft. from the top, very rare ; 25 ft., very rare ; 20 ft., fre- 
quent ; 12 ft., frequent ; 6 ft., rare. 
Gristellaria rotulata (Lamarck) var. macrodiscus Reuss, 
plate I. fig. 9 a, b. 
G. macrodisca Reuss, 1862, Sitzungsb. d. k. Ak. Wiss. Wien, 
vol. xlvi. p. 78, pi. ix. fig. 5 a, b. G. macrodisca Berthelin, 1880, 
Mem. Soc. geol. France, ser. 3, vol. i. No. 5, p. 48, pi. iii figs. 6-11 
and 14 a, b. G, rotulata Burrows, Sherborn, and Bailey, 1890, Journ 
Roy. Micr. Soc., p. 559, pi. x. fig. 17 a, b. 
The above variety, which hardly possesses the specific differences 
seen in it by previous authors, is distinguished from the type form by 
the nearly circular periphery, the greater breadth of the chambers, 
* Journ. Roy. Micr. Soc , 1890, pi. x. fig. 17 a, b. 
