Silurian Rocks of WhitHrsea. 217 



Slmmakt of COXCLISIOXS. 



The Silurian rocks uf the district consist structurally of a jrreut 

 anticlinal fold, called the Whittlesea Anticlinal, and an important 

 synclinal fold, called the Merriang Synclinal, separated by a 

 strike fault. 



PaUieontologically they can be sulidivided into the Mel- 

 bournian series (coincident with the Whittlesea Anticlinal) and 

 the Yeringian series (to which part of the Merriang Synclinal 

 belongs), such s/eries being divided by probable Passage beds 

 containing a rich fauna. 



The estimated thickness of the Melbournian series is between 

 7000 feet and 8000 feet, while that of the Yeringian is about 

 750 feet. 



A shelly limestone forming part of such Passage beds is the 

 most striking lithological feature. 



Finally, I wnsh to express my indebtedness to Mr. Chapman 

 in connection with this paper. He has not only most willingly 

 examined axid determined all fossils submitted to him, but has 

 throughout my work, aided me with his advice and encourage- 

 ment. 



Notes on a Collection of Silurian Fossils froiu tJte 

 Whittlesea District, made by Mr. J. T. Jatsoa. 



By FREDERICK CHAPMAN, A.L.S., Etc. 



(National Museum). 

 (Plates IV., v.). 



Preliminary Re.marks. 



The following determinations have been made upon a veiy 

 representative series of fossils from both divisions of the 

 Silurian, the Melbommian and the Yeringian ; whilst there also 

 seems to be a special fauna represented at the localities near the 



