A MONOGRAPH OP THE TERTIARY POLYZOA OP VICTORIA. 107 



This is a common Australian living species, forming small, simple or branched 

 clusters on other calcareous polyzoa, mostly Adeona and Hornera. The zooecia are 

 much confused, oblique or erect, usually smooth, and with a few round pores. The 

 oral avicularium is not always present even in recent specimens. It is originally 

 situated at the side of the primary thyrostome, and as the peristome is developed it 

 is carried upwards in a semispiral manner, its course being usually marked by a 

 slender tube. The ooecium forms an enlargement on the front of the zooecium, the 

 most prominent part being closed by a disk-shaped convex membrane, chitinous, 

 and becoming calcareous with age in recent specimens, in the fossils calcareous, and 

 usually marked with concentric grooves or pores. 



Cellepora, Fabricius. 



Zoarium crustaceous, adnate, or glomerulous, or foliaceous and partly free, or 

 erect and ramose. Zocecia, in the crustaceous and foliaceous forms, erect and 

 confused in the central parts, decumbent at the growing edges ; thyrostome with 

 the lower lip entire ; one or more rostral processes (frequently absent), usually 

 bearing avicularia in the neighbourhood of the thyrostome ; other scattered 

 avicularia of various forms. 



1. C. audita, n.sp. PI. XIV., fig. 3. 



Zoarium encrusting. Zooecia rounded, erect, bases confluent, surface smooth 

 or slightly granular; thyrostome large, subcircular, peristome not thickened or 

 produced ; no avicularia or rostra in the specimens seen. Ooecia hemispherical, 

 immediately below the thyrostome, with no visible external opening, surface 

 with fine striie radiating from opposite the middle of the lower lip. There are 

 occasionally a few small pores towards the margins of the zocecia, and others, 

 mostly larger, between them. Some of the latter may possibly be avicularian, 

 but I think not. 



S.P. 



I refer this species doubtfully to Cellepora, and it might perhaps be advisable 

 to found a new genus for its reception, characterised by the subcircular thyrostome, 

 destitute of peristome, and the absence of rostra or oral avicularia. 



2. C. trideuticulata, Busk. PL XIV., figs. 4, 5, 6. 



Cellepora tridenticulata, Busk, C.P., Pt. I., p. 198; McG., P.Z.V., 128. 



Zoarium small, encrusting. Zocecia irregularly arranged, confused ; thyrostome 

 arched above, straight below, with three, or occasionally four, quadrate denticles on 

 the lower lip ; 2-1 spines articulated above ; a small avicularium, usually on a raised 

 process, below the mouth. 



P2 



