A MONOGRAPH OP THE TERTIARY POLYZOA OP VICTORIA. 137 



is pitted with numerous rounded pores. The texture of the surface in the two sets 

 of zocecia is identical, and as the ridges are prolonged from one set to the other 

 without interruption, and no bounding line can he seen between a zooecium and the 

 one it is overgrowing, it does not appear possible to regard it as an incrustation of 

 one species on another. 



The zooecial wall of the younger series grows forwards and covers over the 

 thyrostome of the older series, the avicularian tube long persisting as a blunt cone. 



The posterior surface of the colony is imperforate and the zooscia are marked 

 out from one another by impressed longitudinal lines, the transverse boundaries not 

 being shown. 



G. ; B. 



Haswellia, Busk. 



" Zoarium composed of short cylindrical branches, spreading in all directions 

 dichotomously, at very open angles. Zocecia disposed verticillately and more or less 

 irregularly quincuncial, with a produced tubular or subtubular and bifid or simply 

 thickened peristome, supporting on each side a small avicularium with a pointed 

 subtriangular mandible. Primary mouth clithidiate, with an operculum of corres- 

 ponding form." — (Busk). 



S. longirostris, McG. PI. XIV., fig. 20. 



Cellepora longirostris, McG., T.R.S.V., Nov., 1884. 



" Zoarium erect, branched, cylindrical. Zooecia elongated, a lateral sinus in the 

 lower lip, with a small avicularium on one side ; on the front of the zocecium a large 

 avicularium with the long mandible directed vertically downwards. Ocecia rounded, 

 flat in front, with a raised rim, inside which is a row of areolae or pits directed 

 inwards." 



S.P. ; M.C. Living. Australia. 



" In recent specimens the mandibles of the zocecial avicularia are narrow and 

 pointed, not broad and rounded as in the fossil." — (McG. ms.). 



2. H. producta, McG. PI. XIV., figs. 16-19. 



"Zoarium small. Zocecia confused, more or less erect; mouth (primary) 

 arched above, with a well-marked small siuus below, peristome thickened and slightly 

 elevated all round ; a suboral rostrum bearing an avicularium on its summit ; 

 scattered, large, spatulate avicularia with a distinct columella." — (McG. ms.). 



S.P.; M.C; B. 



T 



