330 



A. W. WATERS ON FOSSIL CHILOSTOMATOTJS 



plagiopora, from the Crag, but differs in having an elongate pore ; 

 Escharipora trifora, Boem., from Sollingen, belongs to one of these 

 forms. The old basal cells, where the oral aperture is obliterated, 

 show a central depression for the pore and avicularium ; and the 

 whole cell stands out in a mamillated manner. 



I have one specimen in which all the zocecia are very much 

 swollen on one side without any protuberance on the other ; and 

 in the same specimen, at the lower part of the avicularium, there are 

 three openings, by which the mandible was probably attached. 



Log. Specimen in the Geol. Soc. coll. from Mount Gambier : but 

 from this alone the detail could not have been worked out. Living : 

 Indian Ocean (B.). 



32. Microporella eerrea, sp. nov. Plate XYII. fig. 72. 



Zoarium erect, in EscJiara-foYm, compressed, few cells. Zocecia 

 indistinct, slightly raised round the oral aperture, depressed towards 

 the centre, with a median pore. Oral aperture rounded on the distal 

 edge, contracted towards the proximal edge, which is straight, thus 

 having the shape of a circle with the lower third cut off. Small, 

 erect, oral avicularia in the aperture, in one row on the right, in the 

 next on the left ; small avicularia and large pores round the raised 

 portion surrounding the aperture ; large zooecial avicularia on the 

 side of the zoarium, with the opening looking downwards. Oral 

 aperture 0-14 mm. at proximal edge, 0*18 at widest part, 0*14 mm. 

 long. 



The large avicularium was (by an oversight) not figured ; but the 

 beak is about as large as an ordinary zooecium, and it is just the 

 same in form as the avicularia of Cellaria ovicellosa, fig. 62. 



This would be Biporula of Hincks ; but as I am doubtful about 

 the necessity for the genus, I at present at any rate do not separate 

 it from Microporella. A reference to my paper " On the Use of the 

 Opercula in the Determination of the Cheilostomatous Bryozoa," Proc. 

 Manch. Lit. and Phil. Soc. vol. xviii. no. 2, pi. i. fig. 28, will show 

 that, in the form of the operculum, Microporella (Biporula) verrucosa, 

 Peach, is very similar to the present species. 



Loc. Fossil: Mount Gambier (Loncl. Geel. Soc. coll.). 



33. Microporella elevata, T. Woods. Plate XYII. figs. 63, 64; 

 Plate XVIII. fig. 90. 



Eschara elevata, T. "Woods, " On some Tert. Austr. Bry.," Tr. Boy. 

 Soc. IST. S. Wales, 1876, p. 2, fig. 10. 



Zoarium in Eschara-form, foliaceous, compressed. Zocecia, in 

 young cells (fig. 90), widely oblong to square, with a large short 

 triangular avicularium pointing inwards on one side of the zooe- 

 cium on a level with the aperture, or frequently one such avicula- 

 rium on each side ; in the old cells the zocecia are indistinct, with a 

 much raised peristome giving a crateriform appearance ; the general 

 surface and the peristome divided by raised lines into angular areas, 

 with one or two pores in each such area ; below the aperture a large 

 pore, which, however, is not always readily distinguished on the front 

 of the zooecium ; but when examined from the interior (fig. 64) the 



