BY W. N. BENSON, 335 



displaced by several cross-faults. In Mr. Carter's property 

 (Portion 58), the limestone comes in a»ain, forming a very im- 

 portant band. This is about a quarter of a mile in length and 

 150 feet thick. Its western end is very highly crystalline, so 

 much so that the rock has passed into a white marble, but, 

 towards the east, it is less crystalline, and consists of an extra- 

 ordinary assemblage of broken fossils. Fragments of large 

 pentameroid shells are the predominant feature, but intermingled 

 with them are abundant masses of Stromatnporoids, of fragments 

 of coral, and even angular or rounded pebbles of chert, the whole 

 giving very clear indication of rather turbulent conditions of 

 formation, as if they were reef-breccias (see Plate xxxiv., fig.l). 

 In spite of this, there is no indication of an unconformity, the 

 radiolarian cherts which lie immediately above the limestone 

 dipping W.25°S. at 70°, those immediately below W.26''S. at 

 65°, which, considering the variability of the dip, may be taken 

 as proof of conformity. Possibl}^ the shallow-water limestone 

 indicates the occurrence of a regression of the sea. In cases 

 such as this there is no reason to. expect a mass of coarsely 

 clastic sediment at the base of the overlying transgressive sedi- 

 ment {see 16, p. 458). 



The second characteristic of this limestone is its remarkable 

 fauna, which is quite unlike that of any horizon yet discovered 

 in the Devonian rocks of New South Wales. The following list 

 indicates the forms recognised by Messrs. Chapman, Dun, and 

 Etheridge. Of particular interest is the presence of Tryplasma^ 

 as determined by Mr. Etheridge, and Chretetes, described by Mr. 

 Chapman.* 



Zaphrentis^ sp.ind. 



Zaphrentis{^ sp. (Sp. et subgen. nov.]). 



Tryplasma sp. Intermediate between T. delicatula Eth.fxl., 

 and T. vermiformin Eth.fil. 



Cyathophyllum sp. 



* In a private communication, Mr. Chapman says — "It is interesting 

 to note your opinion of the hj^drographic conditions at Loomberah. 

 Ch(xtetes, to my mind, played the same part in the coastal reefs of the 

 Palteozoie, as HtUoporu does at the present day,"' 



