144 Proceedings of the Royal Society of Victoria. 



Locality. — Mitchell Rivei' (J. Dennant). 



This is found in a very fragmentary state ; the fragments 

 being very long in proportion to their width, the zoaria were 

 probably dendroid. On one, or both sides of the zooecia there is 

 a perforation, irregularly shaped, which may have been caused by 

 the fracture of an avicularium. 



Retepora airensis, n. sp. (PI. XVII., Fig. 9). 



Zoarium reticulate (?). Zooecia about two or three abreast, 

 elongated, irregularly hexagonal, witli raised margins; surface 

 slightly depressed and covered with concave granulations. 

 Thyrostome suborbicular, with raised, wavy edged peristome, 

 generally having a pointed mucro at the proximal edge. A large 

 raised avicularium below, with slightly curved mandible pointing 

 proximally. Dorsal surface vibicate, granulated. 



Locality. — Aire Coastal Beds (Hall and Pritchard). 



This, if reticulate, must have had the fenestrae very large, 

 compared with the trabeculae, as the specimens are all in frag- 

 ments and only a few show any signs of branching. 



Retepora delicatula, n. sp. (PI. XVIL, Fig. 10 and lO.z). 



Zoarivxm dendroid (?). Zooecia in single series, elongate, oval ; 

 surface smooth. Thyrostome with raised, thin peristome with a 

 deep sinus below. Very large, raised, vicarious avicularia with 

 long sliglitly curved mandibles pointing proximally. 



Locality. — Aire Coastal Beds (Hall and Pritchard). 



This is a very delicate species and evidently dendroid ; the 

 avicularia are very prominent and rival the zooecia in size. The 

 two figures given are of the same specimen tilted over laterally, 

 the angular difference being about 45 deg. 



Retepora arborescens, n. sp. (PI. XVII., Fig. 11 and \\a). 



Zoarium dendroid. Zooecia elongated, surface covered with 

 lai'ge, convex granulations. Thyrostome suborbicular ; peristome 

 much raised, having a wide sinus proximally. Large, raised 

 avicularia with long mandible pointing proximally on some por- 

 tions only of zoarium. Dorsal surface vibicate, granulated. 



