33 
Ohs. — This is a compact and uniformly- grown coral, the corallites 
when seen in weathered specimens, transverse to the direction of growth, 
presenting to the naked eye a gemmuliferous appearance, arising from the 
great difference between the size and shape of the autoporcs and that of the 
mesopores, and the limited number of the latter ; this resemblance is increased 
by the re-entrant spaces in which the mesopores are situated. 
The limited number of corallites in a chain gives rise to an interesting 
point of structure, in that the gonopores predominate over the mesopores, so 
much so that it is verv difficult to obtain a longitudinal section of one of the 
latter ; when, however, this is accomplished, the diameter of the tubes, and 
distance apart of the tabulae, will readily distinguish the mesopores. 
No difficulty need occur in distinguishing R. pycnoblastoides from the 
highly farcimcntiform non-septate II. Siissmilchi. The former is — (1) a much 
stronger and more robust species ; (2) the fenestrules are constantly and 
uniformly larger, and with a diffierent outline; (3) the fenestrulc walls arc 
more strongly corrugate ; (4) the autoporcs are oval in the former, round in 
the latter ; (5) the re-entrant spaces containing the mesopores much more 
defined in the latter than in the former. 
The first three points will also assist in distinguishing the present 
species from H. orthopteroides, as well as the form of the autopores in the 
latter, the triangular outline of the gonopores and slit-like mesopores. 
The principal features to be noticed in R. pycnoblastoides are : — (1) the 
generally small size and non-angular outline of the fenestrules ; (2) highly 
farcimentiform outline of the corallite chains ; (3) plentitude of autopores, 
but the limited number in each chain ; (4) copious development of gonopores ; 
and (5) the less development of mesopores, and absence of septa projecting 
from their walls. 
The outline of the autopores and the large square mesopores place this 
near R. catenularius, var. nitida, Lambe, 1 and the longitudinal sections of the 
two are by no means unlike either. On the other hand the dimensions of the 
respective parts do not agree. 
Loc. and. Horizon. — Bed d, Spring Creek, Portion 221, Ph. Barton, 
Co. Ashburnham (J. M. Curran and C. A. Siissmilch) . 
Collections. — Australian Museum and Technical College, Sydney. 
1 Lambe, Contrib. Canadian Pal., 1S99, IV r , Pt. 1, pi. iv, f. 2 a and b. 
E 
