viii LIST OF ILLUSTRATIONS 



PLATES PAGE 



VIII. Examples of State Quarry Ctenodipterine dental plates 324 



The specimens illustrated in this plate, with the exceptions of 

 Figs. 16, 20, 29, 34, belong to Conchodus variabilis, sp. nov. 

 Figures 16, 20, 29 and 34 represent specimens of Synthetodus 

 calvini. All from the State Quarry beds near North Liberty, 

 Johnson county, Iowa. 



IX. Examples of State Quarry Synthetodont dental plates 328 



Plates belonging to Synthetodus trisulcatus, with the possible 

 exception of figures 19 and 32, which may be referable to 

 Synthetodus calvini. All from the State Quarry beds of John- 

 son county, Iowa. 



X. Examples of State Quarry Synthetodont dental plates 332 



Plates belonging to Synthetodus calvini and Synthetodus trisul- 

 catus, all from the State Quarry beds of Johnson county, Iowa. 



XI. Examples of State Quarry Synthetodont dental plates 336 



The smaller plates are determinable as belonging to Synthetodus 

 trisulcatus, the larger ones as examples of Synthetodus calvini. 

 All from the State Quarry beds of Johnson county, Iowa. 



XII. Examples of State Quarry Synthetodont dental plates 340 



Lower and upper pavement dentition of Synthetodus calvini, 

 with the exception of Fig. 16, which is a calcified vertebral body 

 whose relations are considered problematical. All from the 

 State Quarry "fish-bed," Johnson county, Iowa. 



XIII. Crania of Rhadinichthys deani, sp. nov 344 



A series of phosphatic nodules from the base of the Waverly, 

 near Junction City, Boyle county, Kentucky, containing 

 Palasoniscid skeletal parts as nuclei. 



XIV. Map showing Professor Schuchert's reconstruction of Middle De- 



vonian palasogeography at the close of Onondaga time 348 



XV. Map showing Professor Schuchert's reconstruction of Middle De- 



vonian palaeogeography at the close of Hamilton time 354 



XVI. Map showing Professor Schuchert's reconstruction of Upper De- 



vonian palaeogeography 360 



