■62 STANLEY SMITH. 



The New South Wales material shows yet another dis- 

 tinctive feature, not peculiar in itself, but a markedly 

 prevalent character of the specimens as a whole, namely 

 the tendency on the part of the septa to terminate within 

 the dissepimental area and not quite reach the epitheca. 



The massive form from Queensland " L. columnar e " 

 exhibits another character which calls for comment, namely 

 the thinness of the epitheca. These divisional walls 

 between the corallites are much weaker than in a more 

 typical example of Lithostrotion, but stronger than in 

 Orionastrcea (Lithostrotion) ensifer (Ed. & H.) in which 

 the epitheca between the corallites is reduced to a mere 

 trace. L. ensifer links Lithostrotion with the typical 

 forms of Orionastrcea, a derivative of Lithostrotion, in 

 which there is no epitheca at all, and in which the septa 

 are perfectly confluent. 1 



All the characters I have brought to notice suggest that 

 the forms are phylogenetically advanced ones. 



Analysis and Comparison. 

 In the following table, I have set out a detailed and 

 critical analysis of topotypes from Queensland and of the 

 specimens from New South Wales from the sections I have 

 had prepared. The measurements and the number of septa 

 stated therein refer in each case to the largest corallites 

 present in the section. 



Disposal of Material. 



The Irejotype of Aphrophyllum hallense and all figured 

 sections of Aphrophyllum and Lithostrotion are in the 

 Australian Museum, Sydney. Duplicates have been placed 

 in the British Museum (Natural History) South Kensington, 

 London. 



1 Q.J.G.S., Vol. lxxii, (1917) pp. 294-303. 



