128 Annals of the Carnegie Museum. 



According to White, the Lower Coal Measures of Missouri may 

 be inferred to have a stratigraphical position, which although subse- 

 quent to the Morris, Brookville, and Clarion Coals of Illinois and 

 Pennsylvania respectively, is earlier than either the Darlington or 

 upper Kittanning Coals. "* From the Darlington Coal Lesquereux has 

 recorded Pecopteris vestita^ recently shown as apt to be confused with 

 Pecopteris pseudovestita White. Since Calamites suckowi and Cor- 

 daites diversifolius have not been described from any horizon as late 

 as the Darlington Coal they may be eliminated, and the species 

 Pecopteris vestita, Pecopteris arborescens, and Neiiropteris scheuchzeri 

 appear as the sole evidence of a transitional flora between the Lower 

 Coal Measures discussed and the Pittsburgh Coal. The latter two of 

 these species were regarded by Lesquereux^ as being characteristic of 

 the Pittsburgh Beds, but their distribution appears to be so generalized 

 as to be almost useless for stratigraphical correlation. Further rela- 

 tions of the two floras may be obtained upon future collections in the 

 coals of the Monongahela Series, when the relations of the Pittsburgh 

 Coal to the other Coal Measures may then be more profitably dis- 

 cussed. 



* Mon. 37. U. S. Geol. Surv., p. 289. 



6 Mon. 37, U. S. Geol. Surv., p. 85. 



^Second Geol. Surv. Pa., Report of Progress, "P," Vol. Ill, 1884, p. 232. 



