354 Geological Society. 



Ovibos nioschatus, described by the autbor in a previous communica- 

 tion to the Society, bad been derived from tbe Forest bed, he first 

 quoted the opinion of Mr. Clement Keid, that that specimen really 

 came from tbe bed in question, and then proceeded to describe a 

 second imperfect skull of the same animal in the University Museum 

 of Zoology and Comparative Anatomy at Cambridge. The trace of 

 red sandy matrix still remaining and the impregnation with iron 

 peroxide showed that this also had been derived from the Forest 

 bed, whilst the presence of marine Polyzoa on the surface and in 

 cracks was considered to prove that the fragments in question had 

 lain at the bottom of the sea, and the sharpness of the angles 

 forbade the supposition that it had been rolled on a beach. The 

 writer inferred that the skull had been dredged, and that it had 

 been originally derived from cliffs near the Dogger Bank before the 

 coast-line had been cut back to its present position. The fragments 

 consisted of the coronal and frontal portions of the skull with the 

 horn -cores and right orbit. It seems of unusual thickness, and the 

 author briefly described its leading peculiarities and measurements. 



2. " Fossil Chilostomatous Bryozoa from Aldinga and the River- 

 Murray Cliffs, South Australia." By Arthur Wm. Waters, Esq., 

 F.G.S. 



The 73 fossils described in tbe present paper were collected by 

 Professor Ralph Tate, and, with few exceptions, are from Aldinga 

 and the River-Murray Cliffs, Australia. 



This collection again furnishes interesting cases of species growing 

 in both the Eschara and the Lepralia form ; but the chief interest 

 is in a number of specimens which grow in a " cupulata " manner, 

 thus in the mode of growth resembling Lumdites. Attention was 

 again called to the fact that though the shape and nature of the 

 zocecial avicularia (onychoctllaria) are characters of the greatest 

 value, yet their presence or absence cannot be made a specific di- 

 stinction, as there are a large number of cases where specimens are 

 found with none or only a few such avicularia, whereas on other 

 specimens of the same species, collected under similar circumstances, 

 they may occur abundantly over the whole colony, or in parts of the 

 colony, in large numbers. 



In tbe ' Challenger' Report, Mr. Busk refers to a slender process 

 rising from the middle of the base ef the avicularian mandible, and 

 names it " columella." This he considers only occurs in one division 

 of the Celleporce, and in this division only in those belonging to the 

 southern hemisphere. This was shown to be by no means the case, 

 as it is found in the mandibles of CeUepora sardomca from the 

 Mediterranean, in two other common Mediterranean Celleporce &c. 

 In many species there is a denticle in this position rising from the 

 calcareous bar which divides the avicularium. This denticle occurs 

 in various genera and species, and may often be found a useful 

 specific character when examining fossils. 



Out of the 220 species now described in this series of papers, just 

 about one half are now known living. 



