Fig. 
. Calophyllum Donatianum, Avmg. Twice the natural size. Humbleton Hill. 
. Petraia profunda, Germar. ‘Thrice the natural size. The dotted line gives a 
Or 
PLATE III. 
restored outline of the lower half. Humbleton Hill. 
. Calamopora Mackrothii, Gentz. Thrice the natural size. Tunstall Hill. 
— — Highly-magnified figure of the tube-apertures, and the 
denticulated dissepiments. 
— — Longitudinal section, twice the natural size, showing casts 
of the tubes. Humbleton Hill. 
— — Highly-magnified view of a section of the tubes, showing 
transverse plates (a), and mural foramina (4). Tunstall 
Hill. 
. Stenopora columnaris, Sch/otheim. Figure (thrice the natural size) of a specimen 
incrusting some encrinal internodes. The tubes are 
in the state of casts. Tunstall Hill. 
os — Magnified view of a specimen, showing mature tubes (q), 
and new tubes (4) originating from the sides of the 
former. Humbleton Hill. 
— = Specimen (natural size) incrusting some encrinal internodes. 
Humbleton Hill. 
. Alveolites Buchiana, Aizg. Nearly twice the natural size. Humbleton Hill. 
= ses Highly-magnified figure showing the tube-apertures (a), and 
tuberculated dissepiments (6). 
= = Diagram showing tubes. 
. Aulopora Voigtiana, K7mg. Thrice the natural size. Humbleton Hill. 
. Synocladia virgulacea, Philips. Natural size. Humbleton Hill. 
