570 Wm. F. Prouty — Meso-Sihirian Deposits of Maryland. 



tiii ii 



Camarotoechia obtusiftlicata,Z-one 

 Camarotoechia sp.noi/. 7-one 



Nucieosplra bis'uormk Z-one, 

 Bolmarates litnulurus 2.0 ne 



Upper Fossil i/e rous Di vis loti 



Middle Barren Dii/isi on 



LoujerFossi hferousDivision 



) Lower Barren Da/ isi on 



Scale 



(1) a lower relatively 

 barren division includ- 

 ing the shales and 

 sandstones up to with- 

 in some thirty feet of 

 the lower " iron ore," 

 which bears locally at 

 its base a few plant 

 remains, the ostracod 

 Berichia lata and the 

 brachiopod Anoplo- 

 theca hemispherica / 



(2) a lower fossilifer- 

 ous division, including 

 the remaining shales 

 below the bottom 

 " iron ore," the ore 

 bed and some fifty to 

 eighty feet of the over- 

 lying shales and sand- 

 stones ; (3) a middle 

 barren division, in- 

 cluding some two hun- 

 dred feet of relatively 

 barren shales and sand- 

 stones; and (4) an 

 upper fossiliferous 

 division, including 

 about one hundred 

 feet of shales and in- 

 terbedded sandstones, 

 replaced by thin-bed- 

 ded limestone toward 

 the top, about which 

 occurs the very 

 slightly fossiliferous 

 top Clinton sandstone 

 (see sect. fig. 3). 



Of the two fossil- 

 iferous divisions, the 

 lower is characterized 

 by a large number of 

 tentaculites and ostra- 

 cods and two species 

 of trilobites. The 

 upper fossiliferous 



