307 



at the ends and bent like a hook. On a single internode there may be up to 6 

 and they arise from quite similar small chambers, which may sometimes be 

 situated alongside the others, sometimes further down on the zooecium. Each 

 distal wall is provided with an oval, multiporous rosette-plate and the distal half 

 of each lateral wall with 2—3 plates with 2-6 pores. In contrast to T. opuntioides 

 these rosette-plates appear only on the abaxial part of the wall. The operculum 

 (fig. 3 c), which is shorter than that of T. opuntioides is not strongly chitinized 

 and has no chitinous arch. The two rounded lateral margins converge distinctly 

 towards the proximal margin and a strong muscular process is placed within 

 each of them. 



The ooecia, which resemble the front part of an antique lamp, project more 

 prominently but are less bent upwards and inwards than in the preceding species. 

 They enclose a triangulai-, rounded cavity and their outer surface is distinctly 

 striated by longitudinal ridges, the separating furrows of which especially in the 

 proximal part contain numerous pore-pits. 



In the colony each internode has a length of 4—5™"", and in each of the 4 

 longitudinal rows there are 3—5 zooecia. 



Port Phillip, Victoria (Miss Jelly). 



In the species of this genus the colony is formed on quite the same lines as 

 in the species of the genus Cellularia, and we may refer therefore to what has 

 been said on p. 212, as also to the figs. 4 a, 4 c of PI. VII, which give longitudinal 

 and transverse sections of such colonies. 



Tubiporella magnirostris Mac Gillivr. 

 Porina magnirostris Hincks, Annals Nat. Hist., 5 ser. XIV, 1884 p. 279, PI. IX, fig. 6. 



(PI. XVI, figs. 5 a-5 d). 

 The zooecia, which have a rhombic outline and a very uneven, but not strongly 

 arched surface, are often partially separated from each other by very large and 

 deep, irregular depressions, but not by distinct, regular sutural furrows. The pore- 

 pits (fig. 5 c) at their bottom each have a large poi'e and their separating, arched 

 network of ridges is beset with large, scattered tubercles; they soon change to 

 deep pore-canals. The distinctly protruding, obliquely ascending, distally directed, 

 cylindric-conical peristome, which has a somewhat concave frontal wall, is not 

 much shorter than the actual zooecium, and its aperture has a triangular, rounded 

 form, as we can distinguish between a more strongly arched anter and a more 

 slightly arched poster. It is provided to a varying extent with scattered tubercles, 

 which appear most numerously and may often be greatly lengthened on the distal 



20* 



