310 EOCENE STRATA IN THE UNITED STATES. [Ch. XVI. 



ascertained in Clarke County, between the rivers Alabama and Tom- 

 beckbee. 



The lowest set of strata, No. 1, having a thickness of more than 

 100 feet, comprise marly beds, in which the Ostrea sellceformis occurs, 

 a shell ranging from Alabama to Virginia, and being a representative 

 form of the Ostrea flabellula of the Eocene group of Europe. In 

 other beds of No. 1, two European shells, Cardita planicosta, before 

 mentioned, and Solarium canaliculatum, are found with a great many 

 other species peculiar to America. Numerous corals also, and the 

 remains of placoid fish and of rays, occur, and the " swords " (fig. 

 237, p. 289), as they are called, of sword-fishes, all bearing a great 

 generic likeness to those of the Eocene strata of England and France. 



No. 2 (fig. 273) is a. white limestone, sometimes soft and argilla 



Fig. 273. 



Bettis Hill. 



Clarke County. ^s?<i N, ^ r ~=^ 



Claiborne. 



1. Sand, marl, &c, with numerous fossils. \ 



2. White or rotten limestone, with Z&uglodon. V Eocene. 



3. Orbitoidal, or so-called nummulitic limestone. » 



4. Overlying formation of sand and clay without fossils. Age unknown. 



ceous, but in parts very compact and calcareous. It contains several 

 peculiar corals, and a large nautilus allied to JV. ziczac ; also in its 

 upper bed a gigantic cetacean, called Zeuglodon by Owen.* 



The colossal bones of this cetacean are so plentiful in the interior 

 of Clarke County as to be characteristic of the formation. The ver- 

 tebral column of one skeleton found by Dr. Buckley at a spot visited 

 by me, extended to the length of nearly 70 feet, and not far off part 

 of another backbone nearly 50 feet long was dug up. I obtained 

 evidence, during a short excursion, of so many localities of this fossil 

 animal within a distance of 10 miles, as to lead me to conclude that 

 they must have belonged to at least forty distinct individuals. 



Professor Owen first pointed out that this huge animal was not rep- 

 tilian, since each tooth was furnished with double roots (see fig. 274), 

 implanted in corresponding double sockets ; and his opinion of the 

 cetacean nature of the fossil was afterwards confirmed by Dr. Wyman 

 and Dr. R. W. Gibbes. That it was an extinct mammal of the whale 

 tribe has since been placed beyond all doubt by the discovery of the 

 entire skull of another fossil species of the same family, having the 



* See paper by K. W. Gibbes, Journ. of Acad. Nat. Sci. Pbilad., vol. i., 1847. 



