342 A SYMPOSIUM 



These same reasons seem to me to apply equally well to the 

 Cretaceous. Although there is a very considerable difference 

 between the upper and lower divisions, it does not seem to me 

 sufficiently great to warrant their elevation to equal rank with 

 Devonian, Carboniferous, etc. I should, therefore, employ 

 Comanche in its original sense as a stratigraphic term, and, as 

 several formations are clearly recognized within the limits 

 assigned to it, T should be inclined to speak of the Comanche 

 Group. 



I should prefer to divide the Cenozoic into Eocene, Neocene, 

 and Pleistocene as the most widely recognizable time units, 

 placing under the earlier term Eocene the subsequently named 

 division Oligocene of von Beyrich and uniting Miocene and 

 Pliocene into Neocene. 



I can see little advantage in the use of the terms Canadian 

 and Trenton, except as group names, to include the Calciferous 

 and other formational divisions. 



I prefer the use of Lower Silurian to Ordovician, as I do not 

 think the term Silurian of Murchison can with propriety be 

 restricted to the Upper Silurian. If the Upper and Lower 

 Silurian are to be raised to period position, and Ordovician 

 used, I think some other name should be substituted for Silurian. 



Wm. Bullock Clark. 



contribution by s. w. williston. 



I am greatly pleased with your attempt to reduce some kind 

 of order out of the chaos that has been made in geological 

 nomenclature. I think no one but the actual teacher of historical 

 geology can appreciate the amount of confusion that now exists 

 and the vexation that it causes both teacher and pupil. 



To the first five questions I am not prepared to offer sugges- 

 tions except this, that it will make very little difference what 

 terms are used for the time and formation, provided there is 

 uniformity. I am ready to accept and teach any system that 

 receives the approval of writers on these subjects, and is used 

 with tolerable fixity and uniformity. 



