BRYOZOA FROM AUSTRALIA. 441 



breaking up recent specimens I found, placed as a nucleus, either a 

 grain of sand or a minute Foraminifer, as shown semidiagramma- 

 ticaily in fig. 12. The first cells are much smaller than the later 

 ones and very shallow ; and the calcareous growth of the Selenaria 

 will completely surround the grain of sand &c. 



I have Cupularia stellata, B., living, from near Capri, which there 

 grows upon small shells and stones, and sometimes only covers 

 the shell ; in other cases, where the stone or shell is small, it spreads 

 over and grows free, thus assuming the form of the Selenariadae. 

 We thus see that at the commencement the mode of growth of 

 the group is truly Membraniporidan. 



In Cupularia umbellata from the Antwerp Crag, and also from 

 the Pliocene of 1ST. Italy, I have found a nuclear grain of sand upon 

 which the colony has grown. 



Stoliczka, when speaking of Lunulites latdorfensis, says (Olig. Bry. 

 von Latdorf, p. 94) that the point of attachment is at the top, and 

 points out that this is curious, as it is usually below ; but surely 

 the fact must be that the upper part has been broken away, and the 

 shell upon which the young colony has grown is thus exposed. 



In my paper on Bryozoa from S.W. Victoria, page 345, I sug- 

 gested that it was perhaps by an error of the lithographer that 

 Mr. Woods's figures of the Selenariadae were drawn upside down ; but 

 as they have been figured and described thus by a large number of 

 our leading authorities, it is as well to point out that the distal end 

 of the zooecium must of course always be that which is nearest the 

 growing end of the colony ; and this we are always able to decide by 

 means of the operculum, as the hinged end will be the proximal, 

 while the free end is the distal or upper end. 



I would ask a question which only those who dredge in Australia 

 can answer. It is whether, since such a form as Selenaria macu- 

 la ta grows upon a grain of sand, we do not thus, by its presence, 

 obtain an indication as to the sea-bottom of the locality where it 

 grows ? 



Selenaria alata, T. Woods, seems very closely allied to this. 

 Width of opesia, at the widest part, 0*19 millim. ; in the middle 

 0-13 millim. The width of the opercular aperture in a recent spe- 

 cimen is 0-12 millim. 



Log. Living : Bass's Strait (B.) ; Holborn Island (Easwell). 

 Fossil : Muddy Creek, Bird Rock. 



60. Selexaria parvicella, T. Woods. 



Selenaria parvicella, T. Woods, " On some Recent and Eossil 

 Species of Australian Selenariadae," Trans. Phil. Soc. Adelaide, 1880, 

 p. 10, pi. ii. fig. 10. 



The specimen from Bird Rock is but badly preserved. A calca- 

 reous expansion, sloping inwards, about half covers the front of the 

 zooecium. The opesia is thus nearly semicircular. Average width 

 of opesia # 19 millim. 



Loc. Fossil : Muddy Creek ( Woods), Bird Rock. 



