2 A MONOGRAPH OF THE TERTIARY POLYZOA OF VICTORIA. 



last-mentioned papers Mr. Waters deals with specimens from various Victorian 

 and South Australian deposits collected by Mr. Allen, Mr. Tenison Woods, 

 Mr. Etheridge, and Professor Tate. 



There can be no doubt that when other deposits from which I have no specimens 

 are examined, the number will be very largely increased. Even of the deposits here 

 dealt with, the only ones of which anything like an exhaustive examination has been 

 made are those at Schnapper Point and Muddy Creek. 



The most marked feature of the fossil species is their striking resemblance to 

 those of the existing fauna. This is shown not only in the number of identical 

 species, but also in the abundance of individuals of the same or closely allied forms. 

 Thus, of the Cheilostomata, among the Catenicellidse which at the present time are 

 almost exclusively confined to the Australian seas, we have no less than forty 

 species ; and in this connection it is to be noted that the only species hitherto found 

 fossil out of Australia are two recently recorded by Mr. Waters from North Italian 

 Deposits in the Vicentine, which are referred to the Upper Eocene. The Adeonae 

 are largely represented and the Peteporse are abundant, as are also Caleschara 

 denticulata, Membranipora radicifera, Selenaria maculata, Steganoporella magnilabris, 

 Porina gracilis, Lekythopora hystrix and various other markedly Australian types. 

 The living Australian Cyclostomata do not present any special characteristics, and 

 there is nothing particularly noteworthy among the fossils. Of the species not 

 peculiarly Australian which are identical with recent species, most are cosmopolitan, 

 as Membranipora savartii, Thalamoporella rozieri, Cribrilina radiata, Micro2)orella 

 ciliata and Lichenopora radiata. 



The age of the deposits has been the subject of a good deal of discussion among 

 geologists. They are now generally referred to the Oligocene or early Miocene, but 

 some are considered by different authorities to belong to the Eocene. It is difficult, 

 however, to believe that any of them can be so old as the Eocene, at least considering 

 it to be comparable to that of Europe. So far as an opinion can be formed from an 

 examination of the Polyzoa, they are not of very different ages. 



The classification adopted is mainly that given in my catalogue of the Marine 

 Polyzoa of Victoria, published in the Proceedings of this Society for 1886, with, 

 however, some modifications. 



The nomenclature is that in general use. The only innovation of any conse- 

 quence I have made is the introduction of the term thyrostome (0v P a, o-ro/xa) for the 

 opening through which the tentacles and oral extremity of the polypide are 

 protruded. The terms orifice, oral aperture and mouth are inaccurate and confusing, 

 and the proposed name will, I think, prove advantageous. 



