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Some Fossils from the Lower Aubrey and Upper Red AVall 

 Limestones in the Vicinity of Fort Apache, Arizona. 



By Albert B. Reagan. 



The Fort Apache region, Arizona, is the home of the White Mountain 

 Apache Indians. The region, as described in the November number of the 

 American Geologist for 1903, is included between the parallels 33° 15' and 

 34° 15', and the meridians 109° 30' and 111°. In this region, practically- 

 all the geological ages are represented from the Archaean to recent. The 

 Carboniferous Age, to which the fossils belong, is represented by the 

 Au1)re.v and Red Wall groups of rocks. Each of these groups is sepa- 

 rated geologically and stratigraphically into two divisions; the Aubrey 

 into the Upper and Lower Aubrey, and the Red Wall into the Upper and 

 Lower Red Wall. The fossils were collected from the Upper Red Wall 

 and Lower Aultrey divisions. Those from each division were collected 

 separately, and their exact position Avill be given in the description. 



FUSULIXA FISCHER (1837). 

 FUSULIXA SECALICA. 



Plate, Figs. 1 a, b. 



White's description (in partj: Shell varying from terete to subglobose, 

 assuming all intermediate fusiform shapes, generally somewhat obtusely 

 pointed, usually having the appearance of being slightly twisted at the 

 ends; septal furrows moderately distinct, extending in more or less direct 

 lines longitudinally, but are a little deflected just at the ends; centrifugal 

 apertures about twice as high as the thickness of the cell-wall covering 

 them, more than twice as broad as high, and of nearly uniform size 

 throughout the whole coil. 



The locular or external aperture is seldom clearly shown upon the 

 fossils. It was apparently linear the full length of the shell until closed 

 by a ncAV longitudinal septum at each side, leaving only a new centrifugal' 

 aperture at the middle, in line with the others. Volutions from five tO' 

 eight; septa from twenty to thirty in outer volution; septa nearly straight 

 at their outer or external edges, but laterally undulating at their inner 

 edges, where they .loin the outer surface of the next volution within. 



