BRYOZOA FROM S.W. VICTORIA, AUSTRALIA. 



311 



nizing this, based his classification mostly upon the form of the oral 

 aperture ; and Mr. Hincks has followed Smitt's example, introducing 

 some modifications. But sometimes there is a peristome obscuring the 

 oral aperture ; so that it is difficult even in receut species to see the 

 sbape of the real aperture, unless there is sufficient material at hand 

 to make the necessary preparations. As an example, in Tubucellaria 

 cereoides, Ell. & Sol., the operculum which closes the primary aper- 

 ture is situated at some distance from the end of the peristome, 

 which is produced into a long tube. In fossils, however, it is 

 sometimes impossible to make out the exact form of the opercular 

 aperture, even when other details are extremely well preserved ; for 

 an example of which I only need refer to Porina clypeata (PI. XVI. 

 fig. 67), in which the details are so well preserved that I think there 

 is no doubt it can be easily recognized when found elsewhere. 



Probably no naturalist at all thoroughly acquainted with the 

 Brvozoa will again attempt to sustain such genera as the old Lepralia 

 and Eschara ; but it may be well to examine carefully the growth of 

 the Bryozoa before we entirely reject the form of the colony as of 

 classificatory value ; for in many cases it may be shown in this way 

 from which part of a zocecium the following zocecium grows. The 

 mode of growth of Lepralia and Eschara indicated no structural 

 difference ; for the young zocecia in both grew out from the same part 

 of the parent cells, and Eschara was only formed of Lepralia-cells 

 back to back, often very slightly attached. For an example of the 

 new zocecia arising in a different manner we may cite Bicellaria 

 and Bugida, and fig. 33, provisionally placed with Crihrillina as C. 

 dentipora. The form of the aperture must be the first consideration ; 

 but especially among fossils we must carefully notice how they grow ; 

 and it is to be hoped that this latter question may soon receive a 

 thorough and conscientious investigation, as it is a point requiring 

 still further elucidation. At one time I hoped to be able to devote 

 some time to this question, which must be a laborious one ; but I fear 

 the state of my health will not allow me to carry it out. 



If the principles of the old classification had been adopted, it would 

 have been necessary to make several new genera ; but workers on 

 recent Bryozoa have already overthrown the classification based upon 

 the zoarial form, and therefore palaeontologists should follow Smitt, 

 Hincks, and others, and describe their species in such a manner, 

 and use such a nomenclature, that fossils can be compared with 

 living species. 



The Australian Bryozoa, both recent and fossil, have been as yet 

 very imperfectly worked out. The most important works concerning 

 living forms are Macgillivray's* papers, and, for the Catenicellidse, 

 that of Prof. Wyville Thomsonf. Prof Hutton has drawn up a list 



* MacGillivray, P. H., "Notes on the Ckeilostomatous Polyzoa of Victoria,' 7 

 Trans. Roy. Soc. Vict. pt. ii. vol. iv. 1860 ; id. " Descr. of some new Genera and 

 Species of Australian Polyzoa," loc. at. vol. ix. 1869 ; id. in ' Prodromus of 

 Zoology of Victoria,' edited by P. M'Coy, decades iii. & iv. 1879. 



t Wyville Thomson, "On new Genera and Species of Polyzoa," Zool. Bot„ 

 Assoc. Dublin, vol. i. 1859. 



12 



