08 Proceedings of the Royal Society of Victoria. 



down as aV)Out a mile and a half west of the town. Selwyn and 

 TJlrieh both state the general dip about Maldon to be easterly, 

 and the former has placed the syncline further west near 

 Muckleford Creek. 



In a mining district, where everyone is a geologist, it is unfor- 

 tunate tliat the geological term "dip" should be, as here, misused, 

 and still moi'e, used in a diflerent sense in Castlemaine from what 

 it is in Bendigo. The strike of our silurian rocks, both upper 

 and lower, is constantly nearly north and south, so that in a 

 mine we generally have two sets of workings. One set ("drives") 

 agrees with the strike, and the other ("crosscuts") with the dip 

 joints. Any bed or vein wdth an east or west inclination is said 

 to "underlie" or "underlay," while any north or south inclina- 

 tion of a vein or dyke is called the " dip " at a given rate. The 

 distinction has, of course, a practical value, or it would not be 

 used. In the Bendigo "saddle-reefs" the miner's "dip "is the 

 geological "pitch." In Castlemaine, a vein with a north-east dip 

 would be said to "underlie" east and "dip" north, the true dip 

 beinsr resolved into two directions at right angles. 



The Graptolite Successiox. 



Mr. G. H. F. Ulrich, in his valuable catalogue above quoted, 

 states that "owing to the absence of distinctive beds, such as 

 conglomerates and limestones, together with the fact, that the 

 same genera and species of graptolites occur throughout the 

 lower silurian series, no means at present (1874) exist for sub- 

 dividing the formation." On first examining the graptolites in 

 the immediate neighbourhood of Castlemaine, I was at once 

 struck by the difierence of the facies from the one I was already 

 familiar with at Bendigo, and a closer examination of the district 

 showed that there was a gradual change in the character of the 

 fauna on going eastward. This discovery was, of course, only 

 made after many long walks and fruitless searches for fossils 

 amongst the rugged hills that surround the town. The spoil 

 heaps of the gold workings, which lie in every direction, are for 

 the most part old and weather-worn. Pyrites, and other easily 

 decomposable minerals, have aided in the work of destruction, 

 and it is consequently an exception to find graptolites in 



