NO. 9 TERTIARY BRYOZOA — CANU AND BASSLER I7 



Affinities. — This species differs from Porina (Acropora) gracilis 

 Milne Edwards, 1836, in its larger micrometric dimensions, in its 

 ascopore, which is a longitudinal slit, o.io mm in length, decorated 

 with two lateral lips, and in the presence of small spathulated latero- 

 frontal avicularia. 



Occurrence. — Balcombian beds at Muddy Creek, and Janjukian at 

 Mount Gambler, Victoria. 



Holofype.— U.S.N. M. nos. 85584, 85585. 



PACHYTHECELLA Bassler, 1934 

 PACHYTHECELLA UNIFASCIATA, n. sp. 



Plate 4, fig. 5 



Description. — The zoarium is free, bifurcated; the branches are 

 somewhat compressed and formed of two longitudinal rows of cells 

 opening only on one side. The dorsal is convex and smooth, except 

 that the outlines of the zooecia are marked off by ridges. The zooecia 

 are indistinct, little elongated, smooth, the frontal is perforated by a 

 large orbicular ascopore. The peristomie is little salient, rather long ; 

 the peristomice is orbicular ; the peristome is thin, nonsalient. 



Measurements.— 



. ( hp = 0.1 S i^ii ^ fLc = o.4^ mm 



Peristomice-< ,^ ^ Zooecium-( , ^ /■ :>\ 



[//'=: 0.1 5 mm I /^=:0.30 (?) mm 



Occurrence. — Balcombian beds at Muddy Creek, Victoria. 



Holotype.— U.S.N. M. no. 85823. 



PACHYTHECELLA ARMATA, n. sp. 



Plate 4, fig. 8 



Description. — The zoarium is free, bilamellar, formed of rather 

 wide, compressed branches. The zooecia are indistinct, elongated, 

 with very thick walls ; the frontal is convex and covered with a large 

 number of shallow pores. The peristomie is formed by the much 

 thickened zooecial walls ; the apertura is buried at the bottom of the 

 peristomie and appears orbicular ; the peristomice is orbicular and little 

 distinct because of the absence of the peristome. On the marginal 

 zooecia the ascopore is replaced by a large triangular, nonsalient, trans- 

 verse, oblique avicularium ; its beak is oriented exteriorly. 



Measurements. — 



■r, • ■ {hp^o.is mm ^ . rL5' = 0.60-0.75 mm 

 reristomice-^ ,, ^^^ „ Zooecium-^ , „ / o\ 



ylp = o.i'^ mm I /2'=:o.35 (?) mm 



Number of zooecia in 4 mm'', 18. 



Occnrroice. — Balcombian beds at Muddy Creek, Victoria. 



Holotype.— U.S.N. M. no. 85822. 



