MARINE MISCELLANEA. 235 
eight and nine inches in diameter, mounted on a short, stout, central supporting 
stalk or pedicle. In addition to presenting the familiar shallow cup-shaped contour 
with raised central ridges common to many species, this Turbinaria possesses the 
notable peculiarity of having the entire outer margin of its rim, to a tolerably uniform 
depth of two inches, developed downwards and inwards again towards its central 
axis, in the form of an ornamental frill or border. This revolute edge, which 
represents the growing margin, is, moreover, decorated with a considerably larger 
number of vertical ridges than are visible on the upper surface of the corallum. 
Overlooking the existence of its revolute border, this specimen most nearly resembles 
the species described in Mr. Bernard’s Catalogue under the title of Turbinaria bifrons ; 
it differs essentially from that type, however, in the relatively minute size and sunken 
character of the polyps cells or calicles and in other details having a purely technical 
importance. This specimen, evidently representing a new and hitherto undescribed 
species, is, pending a full description elsewhere, provisionally associated in this volume 
with the title of Turbinaria revoluta. 
Shark’s Bay can boast of some notable sponges as well as corals. One of the 
most remarkable of these is figured in the illustration overleaf. By a singular 
coincidence, the type of this sponge was originally described by the author in the 
“Proceedings of the Zoological Society for the year 1871,” under the name of 
Caulospongia verticillata. The specimen, while vaguely labelled “ Australia,” was from 
an unknown locality, and was placed in the author’s hands for description by 
Dr. J. E. Gray, F.R.S., then Keeper of the Zoological Department of the British Museum, 
in which Institution the writer was, at that time, an assistant. That originally 
described type measured but little over a foot in length, and comprised but a single 
apical cone. The specimen of the same sponge with an authenticated habitat recently 
added by the writer to the National Collections is upwards of three feet in height, and, 
in addition to the main central cone, has two smaller ones, each about the size of the 
original type specimen, symmetrically developed on either side of the central one. This 
sponge, it may be added, belongs to the so-called “ Horny ” or ‘“ Keratose” group, in 
which the sponge skeleton is composed mainly of horny matter, after the manner of that 
of the sponge of commerce, Euspongia officinalis. The striking feature in the present form 
is that it consists of a central more solid stalk-like axis, around which are developed 
closely growing flattened whorls or verticils of the finer tissues. The author was more 
especially indebted for the acquisition of this fine sponge to Mr. Ludwig Stross, a 
former resident at Fresh Water Camp, Shark’s Bay. 
