64 



ME. A. W. WATERS ON TERTIARY CHILOSTOM ATOUS 



60. SCHIZOPORELLA CIRCINATA, MacG. (PI. VIII. fig. 41.) 



Lepralia circinata, MacG., Nat. Hist. Victoria, dec. iv. p. 21, 

 pi. xxxv. fig. 1. if 



Schizoporella circinata, Busk, 1 Challenger' Rep. of Polyzoa, p. 166, 

 fig. 46 ; Hincks, Ann. & Mag. Nat. Hist. ser. 5, vol. xv. p. 253, 

 pi. vii. fig. 1. 



This is a common fossil from Waipukurau, and in size is just the 

 same as recent specimens from Napier. The long spatulate avicu- 

 larium, directed downwards, is usually present ; the oral aperture 

 (0'07 millim.) is about half the size of that of S. Oecilii, Aud. 

 Mr. Busk describes in both of these a movable appendage jointed to 

 the operculum : but neither of them is figured correctly by him, as 

 in S. Cecilii the appendage is a broad plate below the operculum, 

 and does not become narrower, as may be seen in the figure given 

 in my paper " On the Use of the Opercula" &c. (Proc. Manch. Lit. 

 & Phil. Soc. xviii. 1878, fig. 1), and in S. circinata it becomes 

 broader below : and this appendage separates very readily from the 

 rest of the operculum, so that it is difficult to prepare them out 

 together. In both there is a small notch in the proximal edge of 

 the larger piece of the operculum, into which the appendage fits ; in 

 S. circinata it is very minute, but in S. Cecilii is much more pro- 

 nounced. It does not seem that this appendage is movable, but that 

 an integument is attached both to it and to the proximal edge of the 

 operculum. In neither have I been able to find the minute fasci- 

 culus of muscular fibres at the lower part of the appendage to which 

 Mr. Busk refers, and such a structure would be very inexplicable. 



Loc. Living : Victoria (MacG.) ; off Inaccessible Island, Tristan, 

 d'Acunha (Chall. Exp.) ; Napier (Miss J.). Eossil: Waipukurau. 



61. SCHIZOPORELLA ATJRICTJLATA, HaSS. 



Loc. Living : European and Australian seas. Possil, Pliocene : 

 Bruccoli (Sicily) ; Reggio (Calabria) ; Mount Gambier and Bairns- 

 dale (Australia) ; Napier and Tommy Gully (New Zealand) . 



62. ScmzoroRELLA R id levi, MacG. ]j"4{ 



Schizoporella marsupium, Ridley, Zool. Coll. made by H.M.S. 

 < Alert,' Proc. Zool. Soc. 1881,'p. 48, pi. vi. fig. 6. 



Schizoporella Ridleyi, MacGillivray, Trans. Roy. Soc. of Victoria, 

 vol. xix. p. 191, pi. i. fig. 1. 



This is a very small species, with the aperture only 06 millim. 

 wide. In the fossil the prominent suboral avicularia cover a large 

 part of the zocecium. 



This seems to be closely allied to S. auriculata, but is smaller. 

 Mr. Hincks (Ann. & Mag. N. Hist. ser. 5, vol. xiii. p. 25) thinks that 

 this is identical with S. (Escliarina) simplex, d'Orb. ; but Mr. Quelch, 

 who has since examined original specimens of S. Riclleyi, combats 

 this (Ann. & Mag. N. Hist. ser. 5, vol. xiii. p. 215). I am not quite 

 convinced that this should not be united with S. simplex, d'Orb. ; but 

 as there is a doubt, it will be best to retain the other name. 



