282 Dr. H. A. Nicholson and Mr. R. Etheridge, Jun., on 



hitherto recognized as an Australian genus of Palaeozoic 

 Corals. Mr. Jack has forwarded to us a single and badly- 

 preserved example, which, although sufficiently good for 

 generic identification, is in too ill-preserved a condition to 

 warrant us in attaching to it a specific description and name. 



The specimen is seated on the weathered surface of a piece 

 of limestone, and exhibits the vermiculate surface and non- 

 septate calices characteristic of Trachypora. 



Horizon and Locality. Arthur's Creek, Burdekin Downs, 

 N. Queensland. Devonian Limestone. 



Collector. R. L. Jack, Esq. 



Genus Aulopora, Goldfuss, 1826. 



(Petrefacta Geruiania3, i. p. 82.) 



Obs. Without at present entering into the question of the 

 extent to which Aulopora, Syrinyopora, and Cladochonus may 

 be regarded as distinct, it may be simply stated that only one 

 species of Aulopora has been described from the Palaeozoic 

 rocks of Australia, viz. Aulopora fasciculata, De Koninck*, 

 from the Upper Silurian of Bell River, New South Wales. 

 We have now to place on record the presence, in the Arthur's 

 Creek Limestone, of a form possessing all the characters of 

 the European Devonian Aulopora repens. 



Aulopora repens (Knorr & Walch.), Edwards & Haime. 



Aulopora serpens, Goldfuss, Pet, Germ. i. p. 82, t. 29, f. 1. 

 Aulopora repens, Edwards & Haime, Pol. foss. Ter. Pal. 1851, p. 312. 



Obs. We have an example of this interesting coral creep- 

 ing over the surface of a specimen of Heliolites porosus. The 

 weathering of the surface of the coral has removed the epi- 

 theca and exposed wall of the Aulopora, and laid bare the 

 interiors of the ramifying or stolon-like corallites. 



The spaces enclosed by the union of the corallites are irre- 

 gular in shape, some polygonal, others elongated. The corallites 

 either occur along the course of the creeping network, or are 

 thrown off as a small projection at each bifurcation. There is 

 no regularity in their disposition : at one point they succeed 

 one another very rapidly along the creeping tubes, and are 

 much crowded ; but on other portions they are scattered and 

 separated by much greater interspaces. On the edge of the 

 corallum, where the reticulation becomes of a more open nature, 

 the zigzag appearance given to the corallites by frequent 

 dichotomization becomes very apparent. There are no septa 

 visible in our example. 



* Foss. pal. Nouv.-Galles du Sud, 1870, p. 14, t. 1. f. 1. 



