22 



establish a distinct fauna— the Spirifer tullius fauna — which 



occupies the upper tour feet of the Moscow shales of this 

 reerion.* The Schizobolus fauna (or faunule) is merely the 

 last phase of this fauna, where Spirifer tullius (Hall) has 

 disappeared, while Schizobolus truncntus (Hall) and Lior- 

 hjrnchus multicostus (Hall) have reached a great numerical 

 development. 



Between Sections 1 and 2, the Moscow shale is exposed in 

 various portions of the stream bed. 



Section 3 (F). 



Plate VI. 



This section extends almost due north and south, and it 

 forms a projecting point, the termination of a semi-circular 

 wooded rock wall, which itself is an extension of Section 1. 

 In front of this cliff is an extensive "flat" or terrace, rising 

 four feet or more above the river bed. The portion of the 

 cliff showing the rocks is only about five hundred feet long. 

 It is kept clear of talus by the stream, which washes its 

 base. The most prominent rock of the cliff is the black 

 fissile and much jointed upper Genesee shale, which here as 

 evervwhere, projects from the bank. The Gray Naples or 

 Cashaqua shales appear above it, and in some parts of the 

 section, a portion of the Black Naples (Gardeau) shales can 

 be seen. The lower Genesee shales form the greater portion 

 of the remainder of the cliff, while only a slight thickness of 

 the Moscow shales appears. The Styliolina projects as a 

 shelf from the bank, and on its under side frequently patches 

 of the -crystalline Conodont limestone appear, never, how- 

 ever, exceeding a fraction of an inch in thickness. The beds 

 dip about one degree to the south. 



Of the Moscow shales, eighteen inches are exposed at the 

 lower (southern) end of the section, and three feet at the 

 upper (northern) end. The shale embraces a very con- 



•For a complete list of the- apecies of this fauna sue- " Faunas of the Hamilton 

 Group of Eighteen Mile Creek and Vicinity." 



