132 CHARLES S. PROSSER 



Dr. Sellards also found well-preserved insects associated with the 

 plants in the Wellington formation of Dickinson County which he 

 contrasted as follows with those from near Lawrence, Kansas: 



The insects from the Marion seem on the whole very different from those of 



the Lawrence shales and other Coal Measure deposits These collections 



[of fossil plants from the Wellington] have since been increased and it may now 

 be said with a good deal of confidence that, although a few species have survived 

 from the Upper Coal Measures, the Marion [Wellington] contains on the whole a 

 distinctly Permian flora. The marked change in the insect fauna in passing from 

 the Lawrence shales to the Marion [Wellington] formation is therefore paralleled 

 by the plant evolution.^ 



This fairly full summary of the conclusions of the various paleon- 

 tologists who have carefully studied the fossils from the deposits under 

 consideration in Kansas and Olilahoma, previous to the publication 

 of my last note on this subject in December, 1907,^ is given in order 

 to show the limits of the Permian as indicated by fossils and that, with 

 the exception of Dr. Girty,'^ all agreed in referring them to the Permian. 

 It is believed by the writer that the above evidence warrants the pro- 

 visional correlation of these Kansas deposits with the Permian, until 

 it is shown by someone that such correlation is erroneous, and that 

 the Permian system extends to the top of the Cimarron series or 

 Red Beds as found in Kansas. References to and quotations from 

 the works of various European geologists who have correlated these 

 deposits with the Permian have been given in earlier publications. 

 Finally, it is to be noted that the fossil evidence now in hand 

 indicates that the base of the Permian system in Kansas begins 

 as low as the Cottonwood limestone, or perhaps a little lower, 

 and that the succeeding rocks in Kansas to the top of the 

 Red Beds belong in this system, because still higher deposits 

 to the south in Oklahoma and the Panhandle of Texas con- 

 tain a Permian invertebrate fauna as described by Dr. Beede. 

 The above-defined deposits are those which I call the Permian system 

 and for which I have accepted the division into two series, viz., the 

 Big Blue and Cimarron, proposed by Professor Cragin in 1906.-* 



I Am. Jour. Sci., 4th ser., Vol. XVI, 1903, pp. 323, 324. 

 = Jour. Geol., Vol. XV, p. 822. 



3 Ibid., Vol. X, 1902, p. 723; U. S. Geol. Surv., Bull. 2IT, 1903, pp. 74-77. 



4 Colorado College Studies, Vol. VI, March, 1896, pp. 3, 5, 18. 



