Sedimentary Rocks. 47 



•difficult. Bendigo, Castlemaine and Darriwil series are all typi- 

 cally represented. The lowest beds seem to be those west of 

 the Djerriwarrh Creek in the south-west < of the mapped area. 

 Beds, probably Middle Bendigonian, and lower than any previ- 

 ously recorded from the district, are indicated by — 



Tetragraptus fruticosus (4-branched), J. Hall. 



Tctragraptus pendens, Elles. 



Phyllograptus cf. typus, J. Hall. 



Goniograptus thureaui, McCoy. 



Goniograptus mace?-, T. S. Hall. 



Didymograptus similis, J. Hall, and others. 



Of Bendigonian age also are the rocks of the south-west bend 

 •of the Pyrete, though the presence of Didymograptus bifidus at 

 .at some outcrops indicates the upper beds of the series just below 

 ^the typical Wattle Gully (Lower Castlemaine) be'ds of Dr. 

 Hall. 9 The beds are in fact transitional between the Bendigo 

 and Castlemaine series. 



Lower Castlemaine beds occur both east and west of these. 

 They were traced for some distance south on the western side 

 <ji the Djerriwarrh Creek, then they outcrop in the bed of the 

 stream, and finally cross it. These beds are of interest on ac- 

 count of their nearness to Upper Ordovician shales — a point 

 to be enlarged on later — and because in them we found a gas- 

 teropod determined by Mr. Chapman to belong to the genus 

 Helicotorna, practically the sole representative at present known 

 ♦of the Victorian Lower Ordovician mollusca. The beds yielded — 



Didymograptus bifidus, J. Hall. 



Didymograptus caduceus, Salter. 



Phyllograptus cf. typus, J. Hall. 



Tctragraptus pendens, Elles. 



Tetragraptus serra, Brong. 



Tetragraptus quadribrac hiatus, J. Hall. 



Clonograptus abnormis, J. Hall. 



Goniograptus crinitus, T. S. Hall. 



Rhino pterocaris maccoyi } Eth. fil. 



Helicotorna sp. 



The presence of D. caduceus with D. bifidus is unusual, but the 

 two species are found together occasionally in the Castlemaine 

 ^district and elsewhere. On the western side of the Bendigo beds 

 we found in Cataract Gully — 



9. 8, pp. 69-70. 



