304 
Notes on the Fossils. 
SPOXGIDA. • 
Genus Receptaeulites Defrance. 
Receptaculites fergusoni Chapman. Plate XLVI. , figs. 1-4. 
Receptaeulites fergusoni Chapman, 1905, Proc. Roy. Soc. Viet., vol. XVIII. (X.S.), pt. I., p. 6, pi. 
II., figs. 1 and 3; pi. IV., fig. 1. 
The type specimen of the above species is a mud cast of the outer wall 
of the sponge. It is, therefore, extremely interesting to find this second 
specimen having the structure of the wall more or less well preserved in 
limestone; although the latter is probably not the original substance of 
its organic framework. 
In my previous description the dimensions of the rhombic plates (of the 
ectorhin) are given as 1.5mm. in longest diameter, and it is there stated 
that “ they do not show much variation in size.” 1 That general uniformity 
in the size of the plates is evidently due to the type specimen showing only 
the basal part of the cup. The plates of the specimen from Loyola are 
from the inner or upper layer of the sponge (endorhin), and are larger 
than the plates formerly described from the ectorhin of the apex, measuring 
as much as 3mm. in diameter. As may be seen, however, the plates 
of both layers would naturally increase in size as they receded from the 
base of the cup. 
The shape of the cup in R. fergusoni is broad and low (as w T ell shown 
in the Loyola, specimen), and with a moderately deep funnel (shown in the 
mud cast). This species differs in a striking manner from R. salteri , of 
the Devonian and. Carboniferous of Australia 2 ; for the boundaries of the 
rhombic plates, as in R. neptuni Defr., are wavy or crenulate. The sliced 
surface of the Loyola specimen shows very clearly the slender vertical 
pillars of the cup, the elongate rhombic form of the plates of the endorhin, 
and the long connecting rays of the four-rayed spicules of the summit 
plates. From the present evidence, this Victorian Silurian species of 
Receptaeulites had an approximate diameter of nearly 6cm. 
ANTHOZOA. 
Fam. Cyathophyllidae. 
Genus Cyathophyllum Goldfuss. 
Cyathophyllum approximans, sp. nov. PI. XLVII., figs. 5, 6. 
Description .-—Corallum compound; consisting of polygonal, usually 
hexagonal corallites, averaging 10mm. in diameter. Primary septa about 
20, moderately thick in median area, becoming thin towards the central 
axis where they are joined in pairs, being slightly twisted'to form a false 
columella. Secondary septa also, thicker in median area, about 20. alter¬ 
nating with the primary and terminating at about two-thirds the distance 
from the periphery to the axis. Dissepiments tending to become vesiculose. 
Epitheca thin. Tendency to separate into corallites very slight. Weathered 
surface of corallum shows corallites with columellar axis and outer portion 
of septa in strong relief. 
1 Loc. cit. p. 7. 
2 Salter, Canad. Ora. Remains, Dec. 1, 1859, p. 47, pi. X., figs. 8-10. Etheridge and Dun, 
1898, Rec. Geo. Surv., X.S. Wales, vol. VI., pt. I., p. 62, pi. VIII.—X. Chapman, Proc. Roy. Soc., Viet, 
vol. XVITT. (N.S.l, pt. T.. 1905. p. 7. pi. IT., figs. 2. 4-7 ; pi. III.; pi. IV., figs. 2-7. 
