27 
in long re-entrant spaces, rectangular and narrow transversely, half to 
one-third millimetres in longest diameter by half a millimetre in width, but 
by a rounding of the angles sometimes becoming oval, occasionally double ; 
visceral chambers transversely oblong ; tabulm complete, close, horizontal, or 
oblique, one-quarter of a millimetre apart. 
Ohs . — Halysites Sussmilchi is so distinct from the other non-septate 
forms, that the points of divergence need hardly be referred to ; however, the 
oval or round outline of the autopores and the re-entrant spaces occupied by 
the mesopores produce equally apparent undulating margins to the fenestrules, 
the mesopores separating the autopores by well-defined interspaces, a very 
different appearance to that noticeable in H. lithostrotonoides, &c. In a 
lateral view of a weathered corallum, the oval or round outline of the 
autopores conveys to the fenestrule wails a highly-ribbed or fluted appearance, 
producing on the whole much the aspect of a sheet of corrugated galvanised 
iron. 
The labyrinthine or irregular outline of many of the fenestrules seems 
to be a prominent feature in this species ; still, there is not the same rambling 
habit of growth as in II. australis, in which the fenestrules are equally 
irregular. Again, like the latter, H. Sussmilchi is one of the forms in which 
secondary silicification has been carried to the greatest extent. The outline 
of the autopores and deep re-entrant spaces between them containing the 
mesopores, resemble those of one of Nicholson’s figures 1 of II. catenularius ; 
similarly, there are no septa. 
Loc. and Horizon. — Bed d, Spring Creek, Portion 221, Ph. Barton, 
Co. Ashburnham (J. 31. Curran and C. A. Sussmilch). 
Collections. — Australian Museum, and Technical College, Sydney. 
Halysites cratus , 2 sp. non. 
(Pi. I, Pigs. 2 and 3 ; PI. IV, Figs. 3 and 4 ; PI. VI, Figs. 5 and 6.) 
Sp. Char . — Corallum massive, forming large tabular colonies of parallel 
and non-radiating corallites up to eight inches by five inches in size. Penestrules 
large, as a rule longer than wide, some quadrangular, a few polygonal, but 
the geometric outline always obscure, the majority being curved, labyrinthine, 
or quite irregular in outline, and often almost linear; sizes 5x5 mm., 
7x4 mm., 6x5 mm., 10 x 1 mm., 11 x 2 mm , 14 x 3 mm. ; margins highly 
1 Nicholson, Tab. Corals Pal. Period, 1879, pi. x, f. 7. 
2 Kp&rvs — “robust.” 
