59 
of the latter species, especially from Tasmania, received through the courtesy 
of Mr. H. M. Johnston, P.L.S., seems to indicate that the fossils known 
under these names should he united. Anticipating other specimens of S. 
Leichliardti from Queensland for examination, this step is deferred pending 
such. 
In our paper^ “On the Tasmanian and Australian Species of the Genus 
Stenopora” Prof. H. A. Nicholson and the Mritcr referred to Tasmanian 
StcnoporcD having the general characters of S. ovata and S. tasmaniensis, hut 
with a compressed corallum, the corallites radiating from both sides of a 
central plane. Mr. 11. M. Johnston has forwarded me similar specimens from 
Porter’s Bay, near Hohart, and IMaria Island, respectively. That from the 
latter locality, and one example from the former, are certainly frondescent, 
i.e., forming flattened tabular expansions of irregular form, as the specimens 
now lie on the surface of the matrix. Certain of the remainder from Porter’s 
Bay exhibit the true characters of S. ovata, although a good deal compressed, 
but it is clear that they are simply compressed stems. On the other hand, a 
larger specimen resembling the latter in its general features may have a 
frondescent corallum, but its present exposure from the surrounding matrix is 
not sufficient to enable me to form a decided opinion. lYe may, therefore, 
conclude, tentatively, that there is the possiliility of both S. ovata and S. 
tasmaniensis possessing an allied species in which the microscopic structure 
is very similar, but with a frondescent corallum. This point only future 
research can decide. Had it not been for corallites opening on both sides of 
a central plane, without definite signs of compression, I should have suggested 
the possibility of this being the base of attachment of S. ovata, but of course 
that one fact is fatal to such an idea, on the supposition of the base being 
encrusting. I am under the impression that the form resembling S. 
tasmaniensis will require to be separated from that species, and should 
investigations, now in progress on the structure of the Tasmanian Stenoporce, 
confirm this supposition, I shall have much pleasure in calling it Stenopora 
JoUnstoni. 
This fossil, of course, brings forward the important question of how 
far outward form can be depended on for specific determination. To a certain 
extent there is no doubt it can — thus, the growth of 8. crinita is in itself 
distinctive, as between it and other species, except 8 . informis, if this be a 
* Ann. Mag. Nat. Hist., 1886, XVII, pp. 175 & 179. 
