The Heathcotian. 175 



Fig. 6. — Diagrammatic section across the silurian rocks from 



Melbourne to Mount Wellington. 

 Fig. 7. — Diagrammatic section from Bendigo to Benambra. 



Plate XXVI. 



Fig. 8. — Cranidium and two thoracic segments of Dinesus ida. 

 Figs. 9 and 10. — Two cranidia of other specimens of Dinesus 



ida. 

 Fig. 11. — Cranidium of Notasaphus fergusoni, showing fixed 



cheeks. Natural size. 

 Figs. 12 a and ^. — Cranidium and pygidium of Notasaphus 



fergusoni. Natural size. The two probably belonged 



to the same individual. 

 Fig. 13, — Pygidium of another specimen of Notasaphus fergusoni. 

 (The specimens on PI. XXVI. are in the collection of the Mines 

 Department, Victoria). 



