A MONOGRAPH OF THE TERTIARY POLYZOA OF VICTORIA. 107 



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

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

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

 oral avicularium is not ahvays 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 zoa3cium, 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, Fabrlcins. 



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

 erect and ramose. Zooecia, 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. ahdtta, n.sp. PL XIV., fig. 3. 



Zoarium encrusting. Zoa-cia rounded, erect, l)ases confluent, surface smooth 

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

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

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

 Avith tine stride radiating from opposite the middle of the lower lip. There are 

 occiisionally a few small pores towards the margins of the zooecia, and others, 

 mostly larger, between them. Some of the latter may possibly l)e avicularian, 

 but I think not. 



S.P. 



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

 to foimd a new genus for its reception, characterised by the suljcircular thyrostome, 

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



2. C. trideuticitlata, Busk. PI. XIV., figs. 1, 5, 6. 



Cellepora trkleuticulata. Busk, C.P., Pt. I., p. 198 ; McG., P.Z.V., 1-28. 



Zoarium small, encrusting. Zooecia 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 



