324 



Report of the State Geologist. 



Brachiopoda : 



* t 



Schizobolus truncatus. r 



R7 



O i 



Ortlmtlipfps arotostriiitfi v 





Clionpfp^ mucronata r 







1 00 



Vy» Iv 1 7 A v 4 C4. • A 



1 0"i 



Kill T*l TP7* 7 il 1 1 P7Yi71 3 tl 1 S H. 



1 06 



^ i*nllinii r • 



k J. LlllllLlo. C 



115 



S. subumbonus. r 



116 



Amboc(jelia umbonata. R 



117 



A. praeurnbona. C 



118 



A. spinosa. r 



1 O 1 



121 



Athyris spiriferoides. r 



lol 



Liorhynchus multicostus. r 



C. 



Transition shales. 



116 



Aniboceelia umbonata (small). R 



117 



A. praeumbona. C 



118 



A. spinosa. r 



121 



Athyris spiriferoides. r 



131 



Liorhynchus multicostus (small), r 



Annelida : 



Conodonts — found only in the shale immediately beneath the concre- 

 tionary limestone layer of Section H. rc 



This is the last of the true Hamilton faunas, and even in this and the 

 preceding, the presence of Schizobolus truncal us indicates a certain transitional 

 character. This becomes strongly expressed in the fauna of the upper foot of 

 shale and limestone, which is here regarded as purely transitional. 



b. The Transition or Schizobolus fauna. 



Between this and the preceding, there is usually a bed of more or less 

 continuous calcareous concretions. In Section H, at Eighteen-mile creek, 

 the characteristic fossils occur in a concretionary argillaceous limestone, which 

 immediately underlies the Conodont bed. The fauna is marked by the 

 extreme development of the three species Schizobolus trancatus, Ambocartia 

 praeumbona and Liorhynchus multicostus. Other fossils are very rare. 



The complete list of the fossils obtained from this bed is as follows : 

 Cephalopoda : 



Orthoceras sp. R 



