144 KANSAS UNIVERSITY SCIENCE BULLETIN. 



The fact that none of the Russian species are identical with 

 any of the Red Beds species and the identity of several of the 

 Russian forms with the Pennsylvanian species found in the 

 rocks below the Red Reds seems to argue a slow migration 

 of the Upper Pennsylvanian fauna to the Russian provinces 

 and a slower migration of the Lower, Middle and Upper 

 Permo-Carboniferous and Lower Permian faunas to the Okla- 

 homa-Texas region. The time lapse of the latter migration 

 is represented by about 2000 feet of strata in the Red Beds 

 region. 



The concurrence of Conocnrdium in these rocks is almost 

 anomalous. I know of but one other place where this genus 

 is represented in the Permian, and that is a very different 

 type of shell found in the province of Palermo, Sicily. The 

 genus is, so far, unknown from the uppermost Pennsylvanian 

 and lower Permian of Kansas. 



The tabulation (page 146) gives the known species from the 

 Red Beds. Those of the Enid formation of Oklahoma are 

 placed in the same heading with the ones from the Wichita 

 and Clear Fork of Texas. Careful detailed stratigraphic 

 work will probably show that the Texas and Oklahoma fossil 

 beds are not from exactly the same horizon as hinted at by 

 Case/** However, they may be combined, if it is understood 

 that it is merely to serve as a convenience here, and that the 

 correlation is only intended in a general way. 



Gould*^ interprets Adams's statements*** concerning the 

 identity of the Albany-Wichita beds as referring them to the 

 Pennsylvanian. On the other hand, I am inclined to consider 

 the statements as non-committal as to whether they are to be 

 classed as Permian or Pennsylvanian. Cummins,*" after 

 demonstrating their identity, unhesitatingly referred them to 

 the Permian. The paleontological evidence certainly bears 

 him out in his conclusions. 



In a letter from Professor Gould, under date of November 

 5, 1906, he gives additional and very good reasons for refer- 

 ring the Wichita-Albany beds to the Pennsylvanian. He 



46. Loc. cit., p. 62. 



47. Water-supp. and Irr. Pap., 15t, p. 17. 



48. Bull. Geol. Soc. Amer., XIV, pp. 191-200, 1903. 



49. Tex. Acad., loc. cit. 



