18 Mr. A. W. Waters on Australian Bryozoa. 
many spatulate avicularia. Ovicell distinct, raised, but partly 
buried in the cell above; its surface is perforated. 
It is very difficult to know where this should be placed ; 
but the appearance and the general characters are decidedly 
those of Smittiéa, as is also the thin operculum; but there is 
no lyrula, and the sinus would make it Schizoporella. Smittia 
obstructa has a semicircular chitinous bar, and a bar also 
occurs across the operculum ot Lepralia mucronata, B.; but 
this is not a common character. 
Smittia obstructa, sp. nov. (Pl. III. figs. 7, 8.) 
The surface of the zocecium is granular, the sides of the 
peristome are very prominent, and sometimes there is a short 
triangular avicularium leaning against each prominence, the 
lower edge of the peristome is continuous, but not much 
raised. 
Ovicells distinct, slightly elevated, proximal and distal 
portion thickened by a subsequent calcification, forming a 
perforated area between. Two or three suboral spines. 
Sometimes a fairly large avicularium on the front of the 
zocecium, and there are a few spatulate vicarious avicularia. 
The operculum is characteristic, being marked by a 
thickened crescentic ridge starting from each lower corner ; 
the rest of the operculum is thin. Lyrula distinct, not large. 
This may be the Smittia trispinosa var. bimucronata of 
Hincks. 
Retepora fissa, MacG. 
Retepora fissa, MacG. Trans. Roy. Soc. Vict. vol. ix. p. 140; ib. vol. 
xix. p. 291, fig. 8; Zool. Vict. dec. x. p. 17, pl. xev. figs. 12-16. 
There is a young colony from Green Point without ovicells, 
and many of the zocecia are unarmed, but some have avicu- 
laria. Two radical calcareous processes are thrown off, and 
there is often a triangular avicularium at the base of the 
fenestra. A young colony like this is with difficulty distin- 
uished from &. avicularis. As mentioned in my Suppl. 
‘Challenger’ Report, it would seem that 2. fissa may be made 
the centre of a group. 
Retepora porcellanea, MacG. 
For synonyms see Waters, Suppl. Rep. on the ‘Challenger’ Polyzoa, 
p. 19. 
Rhynchopora profunda, MacG. (PI. II. fig. 15.) 
Rhynchopora profunda, MacG. Trans. Roy. Soc. Vict. vol. xix. p. 193, 
pl. ii. fig. 8; Waters, Ann, & Mag. Nat. Hist. ser. 5, vol. xx. p. 196, 
pl. vi. figs. 11, 16. 
