286 
NOTES AND MEMLOEANDA. 
Appended to the paper is the following summary of the author’s 
conclusions : — “ In this communication we have first given an epitome 
of the very diverse views held regarding Stromatopora up to the 
present time. We then treat of its fossil state, and show that, although 
the remains have been preserved in several mineral conditions, never- 
theless the skeletal organization originally has been solely of a 
calcareous nature. We further contribute data bearing on the struc- 
tural peculiarities, not only exteriorly and general, but as elucidated 
by microscopic research. It results that neither are the horizontal 
larninfe always porous, nor the vertical pillars usually tubular, as 
some have asserted. In one peculiar aberrant form, Cannopora, there 
are, in addition, large thick walled tubes penetrating the mass 
vertically, and undoubtedly belonging to the organism itself. In 
some forms, notably the genus Stromatocerium, there is a system of 
more or less perpendicular canals and lacunae without walls ; in 
others there is a paucity or even absence of such, though, in most, 
smaller and larger apertures open superficially. A further system of 
stellate obliquely-disposed canals exists, in many forms, both deeply 
and on the surface of the outer layers. While the typical Stromato- 
pora are characterized by horizontal laminas, supported by short 
upright pillars enclosing cuboid chambers or cells, some take on 
a vesicular character {Clathrodictyon), and others (Pachystroma) are 
destitute of pillars. Still other examples, essentially Stromatoporoid 
in aspect, &c., assume a more indefinite minute structure, with a 
tendency to a reticulate or trabecular formation. In certain forms 
(notably Stylodictyon) a columnar character obtains, the chambers 
showing a concentric arrangement round a dense but reticulate 
centre. Thus by their intimate structural peculiarities we attempt a 
tentative classification, wherein we can distinguish at least seven types 
of construction, which we rank provisionally as genera, and we 
describe en passant a few new and remarkable species. 
In discussing the affinities of Stromatopora and its allies, we 
bring forward such evidence and argument as we believe is sufiicient 
to warrant our excluding them in the meanwhile from alliance with 
the Nullipores, the Foraminifera, the Hexactinellid Sponges, the 
Polyzoa, the Corals, and certain fossil forms of uncertain afiinities. 
As respects their Hydrozoal connection, we express ourselves with 
greater reticence, inasmuch as in both Hydractinia and Millepora not 
only are there certain superficial resemblances of considerable im- 
portance, but through the curious divergent form Cannopora structural 
peculiarities present themselves which possibly point to Hydrozoal 
relationships. Moreover, Mr. Carter’s late very shrewd observations 
among the chitinous and calcareous Hydractinice necessarily render the 
object at issue open to further research before the decided negative 
can be affirmed. Mr. Moseley’s * able investigations on the Hydro- 
corallinse during the ‘ Challenger ’ Expedition, while they yield 
valuable hints, do not yet aftbrd all that is desirable to unravel the 
knotty point. It is possible, though, that his future investigations of 
the ample material brought home may supply facts bearing more 
* ‘ Pliil. Trans.,’ 1876, vol. clxvi. pp. 91-129, pis. 8 and 9. 
