334 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



Shota (smoke) Mountains, southwest side of Smoky River, below 

 mouth of Cahnnet Creek (pi. 57. fig. i). 



Tail (moose) Mountain (8,817 feet), peak southwest side of 

 Moose Pass (pi. 55, figs, i, 2; pi. 56, fig. i). 



NEW FORMATION NAMES 



tEET 



ROBSON LIMESTONES.— [Ordovician] massive and thin-bedded lime- 

 stones forming the upper portion of Robson Peak. 



Estimated thickness 3,000 



Fauna. — Fossils occur near the base where there is a commingling 

 of Upper Cambrian and Ordovician types ; also from higher up, 

 where numerous Lingulae of Ordovician characteristics occur. ^ 



LYNX LIMESTONES.— [Upper Cambrian] thin-bedded gray and 

 bluish-gray limestone with bands of shale. 



Estimated thickness 2,100 



Fauna. — None found. 



Name derived from Lynx Mountain, which is almost entirely 

 formed of the strata included in the formation. 



TITKANA LIMESTONES.— [Middle Cambrian] massive beds of thin 

 layers of bluish-gray limestone, interbedded with bands of 

 dolomitic limestone. 



Estimated thickness 2,200 



Fauna. — Characteristic Middle Cambrian fossils, which may be 

 compared with the fauna of the Stephen formation that occurs 

 200 miles (321.8 km.) to the south. 

 Name derived from Titkana Peak, where the formation is exten- 

 sively developed. 



MUMM LIMESTONES.— [Middle Cambrian] massive-bedded gray 



arenaceous limestones. 



Estimated thickness 600 



Fauna. — No fossils. 



Nanie derived from ]\Iumm Peak, where the limestones form the 



upper part of the mountain. 



KITKA FORMATION.— [Middle Cambrian] alternating bands or thin 

 layers of arenaceous limestones and shales. 



Estimated thickness 1,700 



Fauna. — No fossils. 



Name derived from Hitka iIMountain that rises above Smoky River 

 Valley east of Mumm Peak and north of Titkana Peak. 



TATAY LIMESTONES.— [Middle Cambrian] massive-bedded gray 

 arenaceous limestones. 



Estimated thickness 800 



Fauna. — No fossils. 



Name derived from Tatay Cliffs, east of Lake Adolphus and north- 

 west of Titkana Peak. 



^ For lists of fossils see detailed geologic section, pp. 336-340. 



