26 EOCENE AND LOWER OLIGOCENE CORAL FAUNAS. 



From the genera represented, we infer that the beds were laid doAvn in 

 water less than 100 fn thorns in depth. 



In Maiyland and "N^irginia, in the Pamunkey formation of r)arton, the 

 following spec/ies are found : 



Flabellum sp. Balanophyllia desmophylluiu M. -Edw. 



Turbinolia acuticostata Vaugban. and H. 



Trocliocyatlius t-larkeaiuis (Vaugbau). Eupsammia elaboiata (Courad). 



Eupsainniia couradi Vaugban. 



The shallow-water forms of Alabama are not present; therefore we 

 infer that the water in the Virginia-Maryland region was deeper. The 

 character of the sediments (glauconitic sands) bears ont this conclusion. 



Bashi or Woods Bluff beds. — Froui Woods Bluft" six specjcs have been collected. 

 They are : 



Flabennm jobnsoiii A'augban. Balanopbyllia desmophylhiiii M.-Edw. and 

 Paracyatbus ingosus A'augban. H. 



Paracyatbus granulosus Vaugban. Balanopby]lia baleana (M.-Edw. and H). 



Haimesiastra'a conferta Vaugban. Eupsammia elaborata (Courad). 



All of these genera excepting Haimesiastnea may occur in shallow or 

 in rather deei) Avater, but probably the water was only moderately deep. 



Hatchetig.ee Bluff beds. — Ouly oue spccles, Madracis r/refforioi, has been seen 

 from these beds. .ludging from the association wdiich this sj^ecies has at 

 Greggs Landing (Ikdls Landing beds), the inference is that the beds are a 

 shallow-wtiter deposit. 



GENERAL CONCLUSIONS REGAEDING THE MIDWAYAN AND CHICKASAAVAN STAGES. 



Fossil corals of tliese stages from only Alabama and Virginia have 

 been submitted to me for study ; therefore any conclusions reached will 

 apply only to those States. 



The character of the sediments of any region gives us much data regard- 

 ing the depths at which the deposits were laid down, but any additional 

 contribution to the subject should be welcome. The data furnished by 

 a study of the corals found in our Eocene deposits lend additional confir- 

 mation to the existing opinion upon this subject. These deposits in Ala- 

 bama are usually of shallow-water origin, and probably none were laid 

 down at a much greater depth than 100 fathoms, while most of them 

 were deposited in water less than 50 fathoms deep. The Maryland- Virginia 

 deposits were almost certainly laid down in considerably deeper water — 

 between 100 and 200 fathoms. 



