BROADHEAD — COAL MEASURES IN MISSOURI. 327 



bed and one 13' bed and other thinner limestone beds; two 

 beds of bituminous shale, and three thin beds of coal. The 

 upper coal bed is scarcely seen on the Missouri River, but 

 thickens eastward. Its principal outcrops are on Platte 

 River and Niagara Creek, near Rochester, and on Third 

 Fork of Platte, in N.E. part of Andrew County. At the 

 above named localities it is from 5" to 10" in thickness, and 

 sometimes divided by thin layers of argillaceous shale 

 abounding in fossil plants. The next coal crops out in No. 

 110, three and a half miles above Weston ; and 97' beneath 

 the last is another bed of 9". 



The limestones of this Group are usually of a light gray 

 or buff and gray color, and are a good building rock. 



The fossils are Spirigera subtilita (Hall), and Productxis 

 Pogersii (Nor. & Prat.) ; Orthisf hemiplicata (Hall) abounds 

 in the lower part; several species of Bellerophon and a 

 Nucula are common in the upper beds, are also found above 

 but are rarely found below this Group. Orthisina 3Iissou- 

 riensis of Swal. is not found above. 



Group E. — Plattsbicrg Group. The most important mem- 

 ber of this Group is the "Plattsburg Limestone," which 

 forms the upper part and is better developed and more 

 easily recognized than any other limestone of the Coal 

 measures. Fossils are abundant, and some of them are 

 confined to this division. Among these are Productus gi- 

 gantissiinus (Swal.), which ranges throughout the entire 

 Group ; also a beautiful shell allied to Pteroperna and Avi- 

 cida. Bryozoa are abundant. The Group also contains Or- 

 this hemiplicata, which does not extend below in the series. 

 A small trilobite occurs in the calcareous sandstone in 

 Platte County. 



The Plattsburg Limestone is found nearly everywhere in 

 Platte County except the western part. The inferior beds 

 pass through the western part of Clay, thence northeaster- 

 ly to vicinity of Plattsburg, thence to the N.E. part of 

 Clinton, thence northwardly through DeKalb, Gentry, and 

 northeastern part of Harrison Counties. 



Group F. — This is 174 feet thick and rather more than 

 one half is limestone. The latter is variable in color, tex- 

 ture and composition, and at the Missouri River bluffs con- 

 tains but few fossils. Two beds of bituminous shale, and 

 some pyritiferous beds occur near the lower part. 



The bed of deep blue cherty limestone found in river 

 bluffs, near Randolph, is probably the equivalent of beds 

 found on Big Creek, Harrison Co., abounding in so many 

 beautiful fossils. At a mill, 4 miles north of Bethany, I 

 obtained many fine fossils, among which are Pr. Norxooodi 

 (Swall.), Pr. cequicostatus (Shum.), several beautiful Cri- 



