A MONOGHAPH OP THE TEKTIARY POLTZOA OF 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 hounding lini^ can he seen hetween a zou'cium and the 

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

 one species on another. 



The zott'cial wall of the younger series grows forwards and covers over the 

 thyrostomc of the older series, the avicularian tuhe long persisting as a hlunt cone. 



The posterior surface of the colony is imperfoi'ate and the zoa-cia are marked 

 out from one another hy impressed longitudinal lines, the transverse houndaries not 

 beiiiEj shown. 



■a 



G. ; B. 



Haswellia, Busk. 



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

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

 irregularly quinciincial, Avith a produced tubular or suhtu1)ular and hifid or simply 

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

 suhtriangular mandible. Primary mouth clithidiate, Avith an operculum of corres- 

 ponding form." — (Busk). 



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



Cellepora longirostris, McG., T.E.S.V., Xov., 1884. 



" Zoaiium erect, branched, cylindrical. Zoeecia elongated, a lateral sinus in the 

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

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

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

 inwards." 



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



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

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



2. II. 2)rodiicta, McG. PL XIV., figs. lG-19. 



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

 arched above, Avith a well-marked small sinus beloAV, peristome thickened and slightly 

 elevated all round; a suboral r(,sti'um bearing an avicularium on its summit; 

 scattered, large, spatulate avicularia with a distinct columella." — (McG. 'H/s.). 



S.P.; M.C; B. 



