114 HISTORICAL (iEOLOCY 



the histurical suh-dix isiou iht' spccit's are arrangecl aeeording to their posi- 

 tion in the scale of Hfe — that is, following a biological classification, the 

 lower or simpler forms being placed first. The diamond-shaped bits of 

 emerald green i)aper attached to some of the specimens indicate those, more 

 than 8,000 in number, known as "types" or "figured specimens," used by 

 James Hall, R. P. Whitfield and others in the original description and 

 naming of species or in their elucidation. 



The upper shelv<'s and the ends of the upright cases contain particularly 

 large or striking specimens of fossils, or blocks of rock illustrating the geolo- 

 gical features of the horizons in which the fossils occur. 



Attention may l)e called al.so to the collection of Michigan copper ores, 

 orbicular granites and diorites from several parts of the world, fossil crinoids 

 from Waldron and ( 'rawfordsville, Indiana, fossil corals from the Devonian 

 reefs near Louisville, Kentucky, fossil crinoids and an immense clamlike 

 shell from the Cretaceous of Xel)raska, fossil plants from Tertiary beds at 

 Florissant, ( olorado. The windows contain some colored transparencies 

 from photographs of interesting scenery in the West. 



[Return to the II (ill of Md.stodons and Maiunioths and turning to the right 

 enter the IJ'est Corridor or Gem Ilali] 



