DEVONIC FISHES OF THE NEW YORK FORMATIONS 



193 



A glance at the following table will sufifice to show the close corre- 

 spondence, as regards at least their vertebrate contents, between the 

 Appalachian Mesodevonic and equivalent horizons of- eastern Canada and 

 central Europe. 



FAUNAL LIST SHOWING DISTRIBUTION OF MIDDLE DEVONIC FOSSIL 



FISHES 



Note added during correction of the proof. Of the genera enumerated in the above 

 list, Acanthaspis occurs also in the Lower, and Onychodus in the Upper Devonic of 

 Spitzbergen, but none have been reported from the Upper Devonic of East Greenland. 



According to a recent communication byDrO. Jaekel [Sitzber. Ges. Naturf Freunde, 

 1906], it appears probable that the scalelike dermal plates referred to Ptyctodus on page 73 

 of this memoir, and illustrated in plate i, figure 6, properly belong to Rhynchodus. They 

 can not possibly, however, be regarded as internal structures, or in the nature of a pectoral 

 girdle, the extensive series of American specimens with which we are familiar being 

 clearly irreconcilable with such an interpretation. Sufficient reason has not yet been 

 shown for doubting the chimaeroid afifinities of Ptyctodonts. 



