NO. 9 TERTIARY BRYOZOA CANU AND BASSLER IQ 



Measurements. — ■ 



C//a = o.i6 mm fL^j^: 0.75-1.00 mm 



Aperture<^ , ^ ^_ Zooeciai , ^ , 



i I la = 0.20 mm I /^ — 0.40 mm 



Number of zooecia in 4 mm', 12. 



Occurrence. — Balcombian beds at Muddy Creek, Victoria. 



Holotype.— U.S.N. M. no. 85825. 



PETRALIELLA TRACTIFERA, n. sp. 



Plate 5, fig. I 



Description. — The zoarium is unilamellar, perhaps orbicular. The 

 zooecia are distinct, separated by a salient thread or by a thickened 

 band, large, elliptical, elongated, swollen; the frontal is a tremocyst 

 with large expanded pores and bearing an orbicular, salient, avicu- 

 larian umbo. The shield is a narrow circular band surrounding the 

 aperture ; it bears from four to six large hollow spines. The aperture 

 is large, circular ; it bears proximally, a small lyrule and two trans- 

 verse cardelles always placed at the same level as the distal border 

 of the lyrule ; the peristome is thin, smooth, salient, strengthened ex- 

 teriorly by the shield. On the dorsal face of the zoarium, the zooecia 

 are distinct, subhexagonal, separated by thickened salient hands form- 

 ing an interzooecial epicalcification. 



Measurements. — 



r//a = 0.1 5-0.20 mm . ['L.cr = 0.75-0.80 mm 



Aperturei 7 ^ .^ ^ ^^ Zooecia^ , ^ 



i 1^/(7 = 0.15-0.20 mm I /^ = o.6o mm 



Number of zooecia in 4 mm', 10. 



Occurrence. — Balcombian beds at Muddy Creek, Victoria. 



Holotype.— U.S. N.U. no. 85824. 



PETRALIELLA (?) DENTICULATA, n. sp. 



Plate 4, fig. 9 



Description. — The zoarium is bilainellar with wide fronds. The 

 zooecia are distinct, separated by a salient thread, very elongated, 

 irregular ; the frontal is somewhat convex, granulose, bordered with 

 areolar pores. The peristomie is long, the peristomice is oblique, very 

 irregular, with proximal border denticulated by two or three salient 

 rounded mucrons. The aperture is buried at the bottom of the 

 peristomie and bears a well-developed lyrule. 



X^ = o.75-i.oo mm 



Measurements. — Zooecium -, , 



/;: = 0.40-0.50 mm 



Number of zooecia in 4 mm", 15. 



Occurrence. — Balcombian beds at Muddy Creek, Victoria. 



Holotype.— U.S.N.M. no. 85826. 



