《STUDIES IN PALEONTOLOGY AND STRATIGAPHY NO.7》

Abstract1

Introduction2

List of localities3

Stratigraphic distribution of species of Palaeacis within the Upper Devonian and Mississippian4

Systematic Paleontology6

Orientation of the corallum of Palaeacis obtusa9

Specific characteristics of Palaeacis obtusa10

Ontogenetic development of Palaeacis obtusa10

Basal attachment of Palaeacis obtusa11

Evolutionary trends of Palaeacis within the Mississippian12

Wall microstructure within Palaeacis12

Acknowledgements13

Glossary of Terms14

References cited15

ILLUSTRATIONS2

1. Map showing localities from which figured specimens were obtained2

2. Stratigraphic distribution and evolutionary lineages of Palaeacis within the Upper Devonian and Mississippian5

3. Apical views of coralla of Palaeacis obtusa showing the mode of corallite addition7

4. Orientation of the corallum of Palaeacis obtusa9

PLATES17

1. Palaeacis obtusa from the late Osagean Floyds Knob Formation (Localities 1 and 2) of Jefferson County and (Locality 3) of Bullitt County, Kentucky and the middle Osagean Culver Springs Member of the Brodhead Formation (Locality 4), Bullitt County,Kentucky; Palaeacis enormis from the Kinderhookian Ridgetop Shale (Locality 7), Paris Landing, Stewart County, Tennessee; and Palaeacis cuneiformis from the Meramecian Salem Formation (Locality 5), Hardin County, Kentucky17

2. Palaeacis obtusa from the late Osagean Floyds Knob Formation (Locality 1) of Jefferson County and (Locality 3) of Bullitt County, Kentucky19

3. Palaeacis obtusa from the late Osagean Floyds Knob Formation (localities 1 and 2) of Jefferson County and (Locality 3) of Bullitt County, Kentucky21

4. Palaeacis obtusa from the late Osagean Floyds Knob Formation (Locality 1) of Jefferson County and (Locality 3) of Bullitt County, Kentucky23

5. Palaeacis obtusa from the late Osagean Floyds Knob Formation (Localities 1 and 2) of Jefferson and (Locality 3) of Bullitt County, Kentucky25

TABLES8

1. Measurements of 40 specimens of Palaeacis obtusa8