8 Mr. A. W. Waters on Australian Bryozoa. 
mandibles in decalcified specimens, and the apertures in the 
avicularia of Inversiula nutriw ave of the same shape. The 
operculum of J. nutriv is very thick round the border, re- 
minding us of the operculum of Diporula verrucosa. 
Although specifically very distinct, Jullien’s species from 
South America and mine from New South Wales seem to 
fall into the same genus, and probably the New South Wales 
species will have to be called TInverstula inversa. I am now 
unable to understand why I placed mine with Porina, but 
when describing it said that I thought it would have to be 
made the type of a new genus. 
Micropora elongata, Hincks. (PI. I. figs. 21, 22.) 
Steganoporella elongata, Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. vi. 
p. 380, pl. xvi. fig. 4. 
Micropore variperforata, Waters, Quart. Journ. Geol. Soc. vol. xliii. 
p. 51, pl. vill. fig. 27. 
From Green Point there are a few zocecia in shape and every 
particular exactly resembling Mr. Hincks’s figure and descrip- 
tion of S. elongata; but on the same shell there is another 
colony in which the surface has numerous similar large 
perforations (opesiules) and similar avicularia, but the 
zocecia shorter and wider. In the more typical specimens 
there is a well-marked “ opesiule”’ at each upper corner, but 
in some cases it cannot be made out, and in others there are 
more than one on each side. 
The number of opesiules has been shown to be variable in 
this and in Micropora lepida, Hincks. Dr. Jullien, however, 
would use the form of the opesiules as the.chief generic cha- 
racter, making out of the Microporide the genera Gargantua, 
J., Calpensia, J., Andreella, J., Woodipora, J., Verminaria, 
J., Peneclausa, J., Thalamoporella, Hincks, Manzonella, J., 
Pergensia, J., Setosella, Hincks. Surely genus manufac- 
turing never has gone and never will go further than this ; 
and as Dr. Jullien has called attention to many anatomical 
points of importance, it is much to be regretted that he should 
be so hasty in his generalizations on classification. 
In its typical form this does not seem at all like IW. cortacea ; 
but when a series is examined there is found to be little 
difference. In older cells of JZ. coriacea the surface of the 
front wall seems almost closed, whereas in the younger zocecia 
the perforations are distinctly seen, and in some zocecia of 
MM. elongata the pores are not large and distinct. 
