Zoology.'] NATUEAL HISTORY OF VICTORIA. {Pohjzoa. 



The zoarium is partly free or adnate, and very loosely con- 

 nected with the object on which it rests. The zocecia are nearly 

 erect, oblong. Each is connected with six others by tubes spring- 

 ing from the bases (not the sides and anterior extremity) of the 

 zocecia, the tubes thus forming a horizontal network from which 

 the zocecia are directed upwards. At each upper angle of the 

 zocecia there is articulated a lanceolate leaf-like process, the upper 

 and narrower end of which forms a rounded knob. This process 

 is hollowed on one surface, and has a prominent ridge on the other. 

 There is no appearance of mandible, but there can be no doubt of 

 its being a modified avicularium. At the base of the zocecium, 

 when viewed posteriorly, several rounded markings or openings 

 are usually seen near the edge, mostly to one side, and they occa- 

 sionally occur also on the sides of the erect part. 



Explanation of Figures. 

 Plate 117.— Fig. 4, anterior view of portion of a specimen. Fig. 4a, portion of the same, 

 more highly magnified. Fig. 4b, posterior view of same. Fig. 5, side view of two zocecia. 



Plate 117, Figs. 6 to 8. 

 BEANIA RADIC1FERA (Hincks sp.). 



Description. — Zoarium attached by numerous radical tubes springing- from the 

 backs of the zocecia ; zocecia large ; aperture entirely membranous or slightly filled 

 in below by a thin calcareous plate ; two very short spines or tubercles above the 

 mouth, and a long, incurved, blunt or occasionally furcate, rigid spine on one side, 

 a short distance below the mouth ; on the opposite side a large, sessile avicularium 

 rising' from a distinct broad base. Ocecia large, rounded, granular and pitted. 

 Posteriorly, the zocecia distinct, but each united by short calcareous tubes with six 

 others, the spaces between the tubes appearing as round deep depressions. 



Reference. — Membranipora radicifera, Hincks, Ann. and Mag. Nat. Hist., 

 July 1881. 



Port Phillip Heads, on mud and sponges. 



This is in many respects a most interesting form, marking, as it 

 does, the transition from Beania (including Diachoris) to Mem- 

 branipora. The zocecia w T ith the slight filling in inferiorly are Mem- 

 braniporidan ; but, although they are united in front, posteriorly 

 they present the characteristic arrangement of Diachoris, the 

 rounded openings seen being the spaces between the connecting 

 tubes of the adjacent cells, which, instead of being long and 

 chitinous, are here short and calcareous. The avicularium is also 



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