390 DEVONIAN FORAMINIFERA, TAMAVORTH DISTRICT, 



Summary. 



The components of the Nemmgha limestone appear to be 

 largely foraminiferal, comprising, so far as the evidence from 

 microscope rock-sections shows, an abundant species of Psammo- 

 sphcera —P. neminghensis; and the following more or less sparsely 

 represented — Valvulina plicata Brady. V. hnlloides Brady, and 

 V. oblouya, sp.nov.; whilst Pulvinulina appears to be present in 

 P. bensoni, sp.nov. 



The genus Psainmosphcp.ra is more at home in deep rather than 

 in shallow water, though it has been found in depths as little as 

 45 fathoms. The other genera indicate a fairly shallow-water 

 habitat. 



One special point of interest stands out conspicuously in the 

 f <n-aminifera of this limestone, viz,, the rather strong resemblance 

 of the rare Devonian foraminiferal fauna to the Carboniferous 

 and higher beds of the Palaeozoic. 



Radiolaria seem to form a considerable proportion of the 

 granules in the Nemingha limestone, but their mineralised con- 

 dition precludes any reference to definite genera. 



As regards the probable depth at which the rock was formed, 

 one might reasonably assume it to be of moderately deep water 

 origin from the occurrence of Psavimosp/ict^ra and the radiola- 

 rians. On the other hand, oolitic grains are indicative of quite 

 shallow-water areas, though this latter constituent is by no means 

 predominant, and may not materially affect the above conclusion. 

 The general condition of deposition must have been such as 

 would obtain in a moderately deep inland gulf with quiet sedi- 

 mentation and accumulation of ooze-forming organisms: and it 

 is just possible that the oolite-grains may have been blown into 

 the area of deposition from dunes of shore-sand origin in the 

 vicinity. 



In conclusion, I would tender my sincere thanks to Dr. Benson 

 for giving me the opportunity of examining this interesting lime- 

 stone, and facilitating this attempt to describe a unique faunula 

 by furnishing the microscope preparations. 



