202 SMITHSONIAN MISCBILLANEOUS COLLECTIONS VOL. 53 



SHALE: 



Feet 



2. Thin-bedded limestones, with partings of greenish, argillaceous, 



and arenaceous shale. Sometimes the shale and at other 



times the limestone predominates ISO 



LIMESTONE: 



3. Massive bedded, gray limestone, similar to the Meagher lime- 



stone, except that it is of a lighter gray color near the top. . 130 

 Annelid trails are abundant and fragments of tribolites. 



SHALE: 



Thin-bedded limestones, with partings of greenish, argillaceous, 

 and arenaceous shale, the limestones predominating. It 

 breaks down readily on the slopes and forms a sloping 

 terrace 2IO 



LIMESTONE: 



5. Massive bedded, fine-grained, gray limestone that breaks up on 



weathering into thin layers from a quarter of an inch to two 

 inches in thickness. They have a very irregular surface, 

 marked by a thin, buflf-colored deposit that fills the annelid 

 burrows and trails, and also occurs as irregular blotches on 

 the surface. 



This belt of limestone is divided into five thick beds that may 

 be distinguished for miles in the clififs. The two lower are 

 usually broken down 55 



Annelid trails are abundant and numerous fragments of trilo- 

 bites. 



SHALE: 



6. Greenish purple and dark gray, argillaceous shales, with thin 



layers of sandstone and arenaceous shale at irregular 

 intervals IQO 



Shale No. 6 is in the same stratigraphic position as the Wolsey 

 shale [Weed, 1900, p. 285] of the Little Belt Mountains section, 

 and the sandstone beneath corresponds stratigraphically to the Flat- 

 head sandstone [Peale, 1893, p. 20] in the same section. The fauna 

 of shale No. 6 on Scapegoat and Gordon mountains, localities west 

 of the Dearborn River section, is, however, entirely unlike that of 

 the Middle Cambrian Wolsey shale, and includes the following 

 species : 



Micromitra (Iphidella) pannula (White) [1874, p. 6]. 



Oholus (Westonia) ella (Hall and Whitfield) [1877, p. 232]. 



Acrotheh colleni, new species. 



Acrothele panderi, new species. 



Wimanella simplex Walcott [1908J, p. loi]. 



Olenopsis ? sp. 



Ptychoparia, sp. 



Albertella Helena Walcott [1908&, p. 19]. 



