10 
considerably extended, the earliest appearance previously recorded being in 
the Jurassic period. Our example appears to be quite typical. With regard 
to its recent occurrence, the habitat of T. papillata is in fairly deep water. 
Occurrence. — In the washed material from Pokolbin. 
Genus — AMMODISCU S, Heuss. 
Ammodisctjs incertus, d' Orbigny , sp. 
Operculina incerta, d’Orbigny, 1839, Foram. Cuba, p. 49, PI. V, Figw. 16, 17. 
Trochammina incerta , (d’Orb.), Bradv, 1876, Carb. and Perm. Foram., Pal Soe. Mon., vol. 
XXX, p. 71, PI. TT, Figs. 10-14. 
Ammodiscus incertus (d’Orb.), Brady, 1884, Rep. Chall., vol. IX, p. 330, PI. XXXVIII, 
Figs. 1-3. 
Observations. — This species is not common in our material, but a few 
typical specimens have been found. The test, in common with those from 
other Carboniferous deposits, is very thin, and generally, exceedingly 
minute. 
Occurrence. — From the decomposed limestone of Wollong. 
Ammodiscus millettianus, Chapman . 
(Plate II, Fig. 3.) 
Ammodiscus millettianus , Chapman, 1898, Journ. R. Micr. Soc., p. 12, PL II, Figs. 6a, c. 
Observations . — The specific characters given in the original description 
of the Gault specimens, and repeated below, apply equally well to the present 
examples, excepting as regards the aperture, which in the Permo-Carboniferous 
examples is obscure. “ Test finely arenaceous, discoidal and battened ; con- 
sisting of a coiled and irregularly constricted tube, making only one or two 
convolutions. Externally the sutural lines are completely covered by the later 
growth, and are only visible at certain parts by slight linear depressions. 
When moistened, the form of the interior of the test can be more easily 
seen.” The diameter of the Gault specimens average about A mm., whereas 
the Permo-Carboniferous specimens have a diameter of nearly 1 mm. 
Occurrence. — In washings from the limestone of Wollong and Pokolbin 
Nos. 2 and 3). Somewhat common. 
