340 



A. W. WATERS ON FOSSIL CHILOSTOMATOUS 



58. Schizoporella submersa, sp. nov. Plate XYIII. fig. 85. 

 Zoarium in EscJiara-ioim, consisting of narrow foliations. Zo- 



oecia suboval, expanded above, contracted below, distinct, sur- 

 rounded by a raised border, partially concave, few pores on the sur- 

 face. Acute avicularium near the centre of the zocecium, sometimes 

 directed diagonally upwards, sometimes downwards. Oral aper- 

 ture very long, rounded on the distal end, with a small sinus on 

 the proximal. The aperture is much depressed, giving the ap- 

 pearance of two wide denticles at the bottom of the oral pit. Aper- 

 ture 0-07 millim. wide, 0'12 millim. long (to end of the sinus). 



The upper part of the zooecium being depressed gives a concave 

 appearance to the zocecia. 



59. Schizoporella conservata, sp. nov. Plate XYIII. fig. 81. 

 Zocecia suboval to oblong, distinct, not much raised, sometimes 



with a median raised ridge extending from the sinus ; a few large 

 pores near the edge ; surface smooth ; three spines above the oral 

 aperture, and one on each side at the base of the aperture ; surface 

 slightly raised below the sinus. Oral aperture semicircular, rounded 

 on the distal edge, straight on the proximal, with a small sinus 

 which widens out below. An avicularium on one or both sides a 

 short distance below the oral aperture ; these vary from short 

 triangular to acute lanceolate, pointing laterally outwards at right 

 angles to the axis of the cell. Ovicells very large, elevated, with 

 the central part plain, and nearly flat, the exterior walls beautifully 

 ornamented with radiating lines with three pores between each. 

 Aperture 0-16 millim. wide, 0*12^ millim. long (to the straight 

 proximal edge). 



When the avicularia are small, they are raised ; but when large, 

 they are immersed. The dorsal surface is hexagonally divided, with 

 an elongate oval space (about half the length of each zocecium) of 

 thinner shell. This perhaps corresponds with the "flattened disk" 

 mentioned by Mr. Busk in Micro-poreXla Malusii, Aud. (Mar. Poly, 

 p. 83); but it is by no means a constant character in Malusii, as 

 the centre of the dorsal surface is usually depressed, with irre- 

 gular elevations near the edge of the zooecium. The structure of 

 the dorsal surface of Schizoporella conservata must probably be com- 

 pared with that of ScJiizoporella, sp., ~No. 56. I presume this spe- 

 cies grew in the Lepralia-iorm. 



Loc. Possil: Mount Gambier (Load. Geol. Soc. coll. and Eth., 

 Jun., coll.). 



60. Schizoporella spiroporina, sp. nov. 



Zoarium cylindrical ; zocecia in annular series of six cells ; series 

 4 7 millim. apart. Zocecia indistinct, except towards the peristome ; 

 peristome much raised in front, but very little behind. Oral aper- 

 ture at the base of the peristome, nearly circular, rounded at the 

 distal end, with a wide sinus at the proximal. Large pores, perhaps 

 avicularian, near the peristome. 



This may be Spiroporina immersa of T. Woods (Corals & Bry. Col. 



