8 
Observations. — This species reminds us to some extent of H. cassis, 
Parker, sp., but is not so elongate, and the chambers are more strongly 
curved. As JI. cassis is isomorphous with Cristellaria crepidula, so our 
specimens of H. polcolbiense may be compared with the shorter Cristellaria;, 
like C. navicula, d’Orb. 
Occurrence. — H. polcolbiense is a common form in the material from 
Pokolbin No. 2 (Mt. Vincent), and also in Pokolbin No. 3. 
Haplopkragmium, ( f . ten uim argo, JBracly . 
(Plate I, Fig. 11.) 
Haplophragmium tenuimargo, Brady, 1882, Proc. Roy. Soc. Edin., vol. XI, p. 715. 
H. tenuimargo , Brady, 1884, Rep. Chall., vol. IX, p. 303, PI. XXXIII, Figs. 13-16. 
The specimen now figured somewhat resembles Brady’s examples ; but 
the spiral commencement, which in our specimen is rather obscure, does not 
seem to be so definitely inrolled as in the recent form. Like the “Challenger” 
examples, our specimen has the lateral edges sharp and jagged. The recent 
forms were taken, as a rule, from fairly deep-water areas. II. tenuimargo 
does not appear to have been previously recorded in the fossil condition. 
Occurrence. — This example was found in the washings of the decom- 
posed limestone from Wollong. 
Genus — PLACOPSILINA, d’Orbigny. 
Placopsilina tenuitesta, sp. 110V. 
(Plate III, Fig. 9.) 
Description. — Test adherent; apparently spiral; consisting of a series 
of convex chambers, often arranged in three successive layers. Structure of 
the test thin, usually arenaceous although occasionally having the inner 
chambers covered by a chitinous investment. Some fairly large stolon 
passages occur in the outer layer of the test. Length of specimen figured, 
•35 mm. ; height, *18 mm. ; thickness of outer test, -01 mm. 
Occurrence. — This interesting form is fairly common in the thin 
sections made from the Pokolbin limestone. 
