162 
CERIOPORID^. 
Distribution. 
Lower Greensand : Farringdon, Berks. 
Figures. 
PI. Y. Fig. 1. The upper surface of a zoarium ; nat. size. 
Fig. 2, part of the surface of the same zoarium ; X 8 dia. Lower 
Greensand : Farringdon. Mantell Coll. 10,298. 
PL Y. Fig. 3. A more tuberous zoarium from the side ; nat. 
size. Lower Greensand : Farringdon. Cunnington Coll. 55,111. 
PL Y. Fig. 4. A young zoarium ; nat. size. Lower Greensand : 
Farringdon. Sharp Coll. D. 7291. 
Fig. 42. A section across part of a' zoarium, showing some 
zooecia cut longitudinally and some transversely ; X 10 dia. Lower 
Greensand : Farringdon. J. Brown Coll. D. 3144. 
Fig. 42 . — Ceriopora farringdonensis ; x 10. D. 3144. 
Affinities. 
The species is a Ceriopora that looks variolate through 
occasional depressions around the larger zooecia, - and the surface 
is sometimes covered with a calcareous layer, penetrated in places 
by the apertures of single zooecia. The nearest ally of this species 
is C. confusa (Lor.), from which it differs by having thick 
moniliform walls to the zooecia and less crowded apertures ; iu 
C. far ring donemis there are about half as many apertures per 
square millimetre as there are in C. confusa. 
LIST OF SPECIMENS. 
10,298. A massive zoarium, the type-specimen. Lower Greensand. Farringdon. 
Mantell Coll. Figd. PL Y. Figs. 1, 2. 
55,111. A more tuberous zoarium. Lower Greensand. Farringdon. Cunnington 
Coll. Figd. PI. V. Fig. 3. 
D. 7291. A young zoarium. Lower Greensand. Farringdon. Sharp Coll. 
Figd. PI. Y. Fig. 4. 
