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Transactions of the Society . 
characteristic is illustrated by M. Berthelin (loc. cit.) on plate i. figs. 
A-F. M. Berthelin also recognizes two varieties of V. truncata , 
one of which he terms “ var. delicate ” and the other “ var. robuste.” 
Both of these varieties are well represented in the series from Folke- 
stone, and since the robust variety is fairly distinct from the delicate 
form (the latter being more like the figure given by Reuss), I pro- 
pose to retain the thinner and neater variety as the type species, and 
to call the coarsely grown specimens V. truncata var. rohusta. This 
separation of the two forms may be useful in studying their zonal 
distribution in the Gault. V. truncata is recorded from the Upper 
Hils formation and the Speeton clay of North Germany (Reuss) ; and 
from the Gault of Montcley (Berthelin). It also occurs not un- 
frequently in the Chalk-marl of Folkestone and the “ Chalk detritus'’ 
of Charing. 
The species V. eurynota, which was described by von Reuss from 
Folkestone,* and which has subsequently been obtained from the 
Red Chalk of Speeton (Burrows, Sherborn and Bailey) f appears to 
be closely related to F. truncata , to which name I have relegated 
the Gault specimens which show a curvature in the line of growth ; 
these varieties are however impossible to separate in a large series of 
specimens. 
V. truncata is found in the Folkestone Gault in zone ii., speci- 
men b, very rare ; zone iii., frequent ; zone iv., rare ; zone v., rare ; 
zone vi., rare ; zone vii., rare ; zone viii., rare ; zone ix., frequent ; 
zone x., very common; zone xi., 45 ft. from the top, rare; 40 ft., 
frequent ; 20 ft., very rare ; 12 ft., rare ; 6 ft., frequent. 
Vaginulina truncata Reuss var. rohusta Berthelin and Chapman, 
plate VIII. fig. 7 a, b. 
Vaginulina truncata (pars) Berthelin, 1880, Mem. Soc. geol. 
France, ser. 3, vol. i. No. 5, p. 40 (“var. tres-robuste”), plate ii. 
fig. 4 a and b. 
This variety differs from the type form of F. truncata in having 
a test of much thicker and coarser growth ; the vertical costulate 
margins and the transverse sutural costas being of thicker proportions 
than in the type form. The whole shell has a rough and ragged 
appearance, and the surfaces between the sutural ridges are in many 
cases deeply excavate. The edge view of the shell on the apertural 
side shows a surface sometimes curiously ornamented with short and 
twisted strigillations. 
This variety was found in the Gault of France ; at Folkestone 
it occurs in zone v., very rare ; zone vii., common ; zone viii., very 
rare ; zone ix., rare ; zone x., very common ; zone xi., 55 ft. from the 
* Sitzungsb. d. k. Ak. Wiss. Wien, 1862, vol. xlvi. p. 90, ph xii. fig. 9. 
t Journ. Roy. Micr. Soc., 1890, p. 559, pi, x. fig. 9. 
