NO. 5 



PRE-DEVONIAN PALEOZOIC FORMATIONS 



295 



In some of the denuded and partially broken down layers, the 

 columns are shown closely packed together ; in places they slope at 

 an angle of 5° to 10° to the surface of the layer, and many of them 

 expand slightly from base to summit, varying in length from 20 inches 

 (50.8 cm.) to 4.5 feet (1.3 m.). In form, some are round and others 

 hexagonal and irregular in cross section ; they may be crowded together 

 or have spaces between them filled with the limestone matrix. Nearly 

 all reach the upper surface of the layer, but a few are shorter and 

 the laminations of the sediment now forming the matrix arch over 

 these as though they projected above the bed of the sea when the 

 sediment was deposited. The only structure preserved is a convex 

 lamination with a slight depression at the center of each column. 



Fig. 28. — CoUcnia ? proUfica new species. Diagrammatic oudine of Collcnia ? 

 beds in which three layers of the deposit are outlined. The middle bed may 

 represent a form distinct from CoUcnia ? prolifica, but slender growths occur 

 in the beds above and below and an occasional broadly expanded column in 

 the middle bed. The only structure features observed are the lamellae of 

 growth. 



Formation and locality. — Same as plates 56, 57. 



In the section of the Sabine formation above Tilted Mountain 

 Falls (p. 291), there are two thick layers of irregular columns some- 

 what similar to those below Cotton Grass Cirque, and a form more 

 like Cryptozoa occurs in the limestones of the Sabine formation of 

 the Ranger Canyon section (p. 264) ; also either in the Sabine or Lyell 

 formation on the upper side of the motor road, 5 to 10 miles (8 to 

 1 6. 1 km.) w^est of Banfif. The outcrops of the Sabine formation 

 occur at Ten Mile Canyon of the Sawback Rang-e above the motor 

 road west of Banfif. 



