Victo7'ian Fossil Seienariidae. 211 



not figure nor mention any spines on the zooecia generally, but, 

 through the kindness of Professor Spencer, I have been enabled 

 to examine the specimen from which Dr. McGillivray's figure 

 was drawn, and on some of the inner zooecia there are traces of 

 spines, so that probably my specimen is a perfect form, and all 

 the others more or less worn. 



S. petaloides, D'Orbigny. 



Lunulites petaloides, D'Orbigny. P.F.T.C, vol. v., p. 353, 

 pi. 705, figs. 6-9. 



Mr. Waters has, in Q.J.G.S., 1883, p. 442, recorded this as 

 from Muddy Creek, and quotes S. cupola, T. Woods, as a 

 synonym, but, as Dr. MacGillivray shows, this is an error, 

 because in S. petaloides the zooecia are distinct behind, which 

 they are not in S. cupola. I have a specimen of S. petaloides 

 from the Beaumaris deposit, in which the outline of each zooecium 

 is distinctly seen on the dorsal surface. 



In my remarks upon S. punctata I have said that it is not 

 found fossil, and that there is an enormous difference in the size 

 of the zooecia of this and the fossil form. I have lately had a 

 quantity of Polyzoa, dredged by Dr. Yerco in South Australian 

 waters, for examination, among which were several specimens of 

 a form allied to S. punctata, in which the zooecia are intermedi- 

 ate in size between it and tlie fossil, namely, 0.3 millimetres 

 wide and 0.2 to 0.25 long; and since then I have received from 

 Mr. Whitelegge another form from WoUongong, N.S.W., in 

 which the zooecia are about the same size. All these forms have 

 two pores in the front wall of the zooecia, but that is the only 

 characteristic in common ; in all other respects they differ from 

 one another. I have therefore considered it advisable to re-name 

 the fossil form S. magnipunctata ; the South Australian form I 

 have named S. bimorphocella, in allusion to the two sizes of 

 zooecia in the adult form ; and the WoUongong form S. parti- 

 punctata, as the vibracular cells are not completely covered with 

 punctures, leaving to the N.S.W. (Port Jackson) form the name 

 S. punctata, by which it was originally described by Woods. 



The following are the descriptions of these four species, and I 

 wish to state that I have used the term " thyrostome " (oral 

 aperture) as it has been applied by Dr. MacGillivray, not only to 



