Zoology.] NATURAL HISTORY OF VICTORIA. [Po/yiofl. 



Plate 175, Fig. 1. 



TESSARADOMA MAGNIROSTRIS (McG.). 



[Genus TESSARADOMA (Norman). (Sub-kingdom Moliusca. Class Polyzoa. Order 

 Infundibulata. Sub-order Cheilostomata. Family Microporellidse.) 



Gen. Char. — Zoarium encrusting, or foliaceous and unilaminate, or erect and ramose. 

 ZocEcium with the peristome produced and turned forwards in a tubular or subtubular manner; 

 a median, tubular, zooecial pore.] 



Description. — Zoarium hemescharine, laro;e, thick. Zooecia large, indistinct, 

 smooth when the thick epitheca is entire, with larg'e perforations when this is 

 removed ; zooecial pore rounded, elevated, hetween the mouth and the middle of the 

 zoceciura ; mouth larg-e, nearly straight below, arched above, peristome raised. 

 On each side of the zooecium, below the mouth, a large avicularium with the long, 

 pointed mandible directed transversely outwards. 



References. — Lepralia magnirostris, P. H. MacGillivray, Tr. Roy. Soc. Vict., 

 July, 1882 ; Porina magnirostris, Hincks, Ann. and Mag. Nat. Hist., October, 1884. 



Port Phillip Heads. 



Forms a thick hemescharine zoarium, the layers being occa- 

 sionally folded and united back to back. The zocecia are large 

 and very indistinct. The whole surface is covered by a thick 

 epitheca on which the only mark seen is the tubular opening of 

 the zooecial pore. When the epitheca is removed, the surface is 

 seen to be covered with large perforations. In old specimens 

 these may be filled in, or even become tubercular from the heaping 

 up of calcareous matter. I have not seen ooecia. 



I have elsewhere shown that the name Porina, originally pro- 

 posed by D'Orbigny (Paleontologie Francaise, v. 432) to include, 

 amongst living forms, P. Africana (D'Orb. ) and. Eschara gracilis 

 (Milne-Edwards), ought to be retained for those agreeing with 

 Milne-Edwards' species in the possession of an external or 

 adventitious pore formed by the growth of the peristome and, 

 therefore, opening externally to the true mouth. Tessaradoma 

 proposed by Norman for another species previously described by 

 Busk as Onchopora horealis and by Sars as Qvadricellaria, clearly 



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