270 E. A. Smith — Remarks on a paper of 0. Meyer. 



Art. XXXIV. — Remarks on a paper of Dr. Otto Meyer on " Spe- 

 cies in the Southern Old- Tertiary /" by Eugene A. Smith. 



In this paper, one of the objects of the author is to show- 

 that the relative position of three of the subdivisions of the 

 Tertiary formation, viz: Vicksburg, Jackson and Claiborne 

 (given in descending order), is not the true one, but that it 

 should be Claiborne, Jackson and Vicksburg, with Claiborne 

 at the top and Vicksburg at the bottom. 



This conclusion of Dr. Meyer cannot be allowed to pass 

 without comment; for although no geologist who has ever 

 been across the country where these rocks occur in Alabama, 

 could for a moment be in doubt as to their relative position, 

 yet those unacquainted with the facts in the case might be led 

 by Dr. Meyer's paper to doubt the accuracy of the observations 

 of Lyell, Tuomey, Winchell and others. 



So far as I am able to make it out, Dr. Meyer's conclusion is 

 based upon two observations, and upon a number of inferences 

 derived from what he thinks should have been the course of 

 evolution of several species of shells. 



The observations are these: (1) Conrad found in one of the 

 lower strata of the Claiborne bluff, below the ferruginous sands 

 which bear the greater part of the well known Claiborne fos- 

 sils, a specimen of Spondylus dumosus ; and (2) Dr. Meyer 

 himself, found a specimen of an Orbitoid in one of the lower 

 strata at Claiborne. I shall say nothing of the possibility of 

 these specimens having been washed down from a higher level, 

 for it is to be supposed that these two observers were not mis- 

 taken as to the actual occurrence of the fossils in the rocks 

 mentioned, nor will I refer to the fact that these two observa- 

 tions, so far as they prove anything, merely show that the two 

 species named have a greater range geologically than has 

 usually been assigned to them, for I know from personal obser- 

 vations near St. Stephens and elsewhere, that they occur in 

 great numbers, above the Claiborne sands also, but shall con- 

 fine myself to stratigraphy, since superposition is after all the 

 only absolute test of relative age. 



The term White limestone, has been applied in Alabama to 

 a series of calcareous rocks over 200 feet in thickness. A 

 portion of the upper part of this is a chalky rock quite soft 

 and easily cut when freshly dug, and much used as material 

 for building chimneys. This upper part also in places contains 

 great numbers of Orbitoides Mantelli. The lower fifty or 

 sixty feet are more clayey, give rise on disintegration to a 

 limy soil which resembles closely the limy soil of the Eotten 



