ALDINGA AND THE RIVER-MURRAY CLIFFS, SOUTH AUSTRALIA. 307 



hoc. Living : Off Cape York, lat. 10° 30' S., long. 142° 18' E., 

 8 fathm. {B.)\ Semaphore, Adelaide {A. W. IV.). Fossil: Aldinga, 

 Eiver-Murray Cliffs (dome-shaped and iucrusting) ; Yorke's Penin- 

 sula (irregular cone-shaped) ; Waiimkerau (New Zealand). 



69. Cellepora fossa, Haswell, Waters, Quart. Journ. Geol. Soc. 



vol. xxxvii. p. 343, pi. xviii. fig. 89, and vol. xxxviii. p. 275. 



From the River-Murray Cliffs there is a specimen about 25 millim. 

 in diameter, with the one surface, which may be called the under 

 surface, flat ; the other is slightly rounded. On the flat surface 

 there are about forty well-marked pits and a few smaller ones. 



Fig. 2. — Zooecium o/CeUepora fossa. (Enlarged 2o diam.) 



Mr. Haswell, in a " IS'ote on a curious instance of Symbiosis " (Proc. 

 Linn. Soc. N. S. Wales, vol. vii. 1882), refers to his discovery of 

 small red Actinids lodged in cylindrical pits in recent Cellepora, and 

 he attributes these pits in C. fossa to a similar parasite. It is 

 therefore extremely interesting to frequently find similar pits in 

 fossil Celleporce. Mr. Busk refers to a perforation two thirds through 

 C. tubulosa, a fossil from Australia, which, however, cannot be 

 identified, as the description only takes cognizance of the mode of 

 growth. 



The straight edge of the aperture is irregularly rough, but there 

 are no teeth. 



Loc. Living : Holborn Island. Fossil : Curdles Creek, Mt. Gam- 

 bier, River-Murray Cliffs, and Aldinga. 



70. Cellepora fossa, Hasw., var. marsupiata, nov. 



Zoarium subglobular (6 millim. diam.), with a central pit as in 

 0. fossa. In the typical C. fossa, the avicularium is very large, 

 often nearly as large as the oral aperture (fig. 2), so that in badly pre- 

 served specimens the appearance is of one large round aperture 

 with a bar across. In the present variety the avicularium is much 

 smaller, with the avicularian chamber raised, forming a kind of 

 pouch with a semicircular aperture (fig. 3). Surface granular. The oral 

 aperture (0' 1-0*12 millim.) is narrower than in C. fossa but is pro- 

 portionately longer ; inside the aperture directed downwards, towards 

 the interior of the zooecium, there is a tooth on each side of the 

 aperture, and sometimes these teeth are continued as a plate round 

 the proximal part of the aperture. In a few cases faint traces of 



