Ordovician Rocks. 61 



line. This northerly occurrence of Didymograptus bifidus marks 

 the apex of a ge-anticline not shown in Messrs. Baragwanath or 

 Herman's section. Several occurrences of D. hifidtis between 

 Chewton and 76i miles indicate smaller anticlines. Near Aber- 

 deen Hill, Middle Castlemaine beds are found, and then, after 

 repetition, an ascending series of Upper Castlemaine between 

 the Vincent Street bridge and the 7T-mile post. The railway 

 soon after this ceases to be of value, and the section has been 

 worked out westward on less complete evidence. The most westerly- 

 occurrence of Middle Castlemaine beds noted in this locality is near 

 New Chum Gully, though isolated outcrops may exist further west. 

 With this exception, all graptolites found between a north and soutlx 

 line through the 77-mile post and the Harcourt-Campbell's Creek 

 railway line are Upper Castlemaine. 



So far the stratigraphical relations of the members of the Castle- 

 maine series and some members of the Bendigo and a higher series, 

 have been traced from the apex of a ge-anticline at the Elphinstone 

 Tunnel exposing Upper Bendigo beds, through a syncline at 73h 

 miles, exposing beds containing Oncograpfi/s and higher than the 

 Castlemaine series, to the main apex of the Chewton ge-anticline 

 exposing Wattle Gully (Lower Castlemaine) beds. These beds recur 

 at intervals for about a mile, and then disappear under higher beds 

 which rest on the western limb of this ge-anticline. 



(h) Wafe?- Race Section. 



Parallel to the whole length of the previous section and mostly 

 within the same compass there is an almost complete section along 

 the water race to the south. It is supplemented in part by outcrops 

 along the ridge of hills between the race and the railway section 

 already traversed in detail and by beds exposed south of the rac& 

 on either side of the Chewton-FryerstoAvn Road. 



Leaving the railway half way lietween tlie 72 and 73 mile 

 posts, Didi/mor/i'a2)fus bifidus is first found, and after an 

 unfossiliferous stretch, several Upper Castlemaine outcrops the 

 first of which, as before mentioned, can be correlated with an 

 outcrop on the railway. The beds then pass through Middle 

 Castlemaine to Lower Castlemaine, several D. bifidus outcrops 

 occurring between White Horse Gully and the Chewton-Fryers- 

 town Road. From this road to the Monk the race is unfossil- 

 iferous, but at the Monk a small outcrop of the Bendigo series 

 occurs, the beds on either side being still Lower Castlemaine. Be- 

 tween the Monk and the offtake of the South Campbell's Creek race 



