70 Review of M. Tuomey 1 s Final Report 



With the account of the eocene strata we have a list of the 

 fossils common to both the burr-stone and the strata of Claiborne, 

 Alabama, which shows conclusively that they are equivalent. 

 This list embraces no less than 58 species. 



Fossils common to the Cretaceous and Eocene formations. 

 The following are given as common to both these periods: 

 Ammonites placenta, Terebratula Harlani, Plagiostoma gregale, 

 Gryphasa mutabilis, Ostrea panda, Trigonia thoracica? and also 

 two species at least of Echinoderms. 



The announcement in this list by Mr. Tuomey, of ammonites 

 common to both the cretaceous and tertiary formations, will not 

 fail to surprise our palseontological readers, as it has been hitherto 



supposed that this genus ceased to live before the period of the 



tertiary deposits. As strong evidence of the existence of this 

 fossil in our tertiary will be required, before its presence there will 

 be admitted, we give Mr. Tuomey's account of the discovery. 



"In 1846, I happened to be in Wilmington during the progress of 

 an excavation in the conglomerate of that place. The excavation was 



made on the side of the hill on which the city stands, and in the upper 

 part of the conglomerate, where it was in contact with the miocene. 

 I found the surface perforated with lithodomous shells of miocene spe- 

 cies, showing that it was the bed of the eocene ocean at the time that 

 the latter formation was quietly deposited in it. 



"I was not a little surprised to find here a Trigonia, at least related 

 to T. thoracica, Mort., if not identical with it, together with several well 

 characterized casts of Ammonites placenta, Dekay, a fossil found in 

 the cretaceous beds of Delaware, and in those of the Peedee, South 

 Carolina. 



11 Seeing that this bed is a conglomerate, I set myself to examine the 

 probability of these fossils being washed from the cretaceous beds, 

 higher up the river, upon which it rests. The conglomerate is com- 

 posed for the most part of rolled calcareous pebbles, agreeing with the 

 mass in which they are embedded, and it is well known that lilhologically, 

 the cretaceous beds of North and South Carolina are entirely different, 

 and hence I could not fail to detect any thing brought from that forma- 

 tion. The casts are composed of the white limestone; and the casts 

 of eocene fossils, with which they are associated, are so perfect, that 

 I was forced to the conclusion, that the molluscs belonging to these 

 shells, lived and died where they are entombed. " 



The fact that ammonites were found only in a bed of con- 

 glomerate, and that Mr. Tuomey himself questioned as to the 

 probability of their having been washed from the cretaceous 

 beds, notwithstanding his conclusion to the contrary, will leave 

 some doubt on the minds of many on this point. Considering 

 however, that there are other fossil species, as the Ostrea panda 

 and the Gryphaea mutabilis, which were certainly contemporane- 

 ous with the Ammonites placenta in the cretaceous period, and 







