694 DR RAMSAY H. TRAQUAIR ON THE DISTRIBUTION OF FOSSIL FISH-REMAINS 



striking difference on the one hand and similarity on the other is due to the conditions 

 of deposit, is clearly shown in the next and following lists of species. 



Gilmerton Ironstone. — Between the two lowest marine limestones (see PL II.) is a 

 well-known coal-seam, the " North Greens," and not far above that is the " Gilmerton 

 Ironstone," which yielded in times gone by a multitude of large bones and jaws of 

 Rhizodus Hibberti and Rh. ornatus, as well as the originals of the labyrinthodonts 

 Pholidogaster pisciformis, Huxley, Loxomma Allmani, Huxley, and Macromerium 

 Scoticum, Lydekker. On my return to Edinburgh in 1874 I found that this ironstone 

 was again being worked at Venturefair Pit, Gilmerton, and, with the aid of some of the 

 miners, enlarged the list of fishes to the following : — 



Acanthodes, sp. 

 Gonatodus macrolepis. 

 Elonichthys Robisoni. 



„ mvltistriatus, Traq. 



Nematoptychius Greenocki. 



Eurynotus crenatus. 

 Megalichthys, sp. 

 Rhizodus Hibberti. 

 „ ornatus. 

 Sagenodus quinquecostatus, Traq. 



Here it will be seen that the Elasmobranch fauna of the marine limestones is utterly 

 wanting, and the estuarine fishes have returned. Of the eight specifically determined 

 fishes of the above list, no less than six are found in the oil shales, including the 

 Wardie beds, below, and consequently must have been living elsewhere in waters 

 adapted to their organisation during the time when the Hurlet Limestone was deposited 

 under true marine conditions on the same spot. 



Edge Coed Group. 



The next bed to be noticed is a " blackband " ironstone near the horizon of the 

 North Coal which has been worked at Niddrie. It is accompanied by a hard grey 

 micaceous shale with Lingula squamiformis, and consequently of marine or brackish 

 water origin. This shale contains, moreover, an interesting set of fish-remains, as 

 follows : — 



Pleuroplax falcatus, Traq. 

 Oracanthus armigerus, Traq. 

 Tristychius arcuatus. 



„ minor. 



Euphyacanthus semistriatus. 



Megalichthys, sp. 

 Rhizodopsis, sp. 

 Ccelacanthus Abdenensis, Traq. 

 Eurynotus crenatus. 

 Rhadinichthys, sp. 



Here we have a fish-fauna which, especially in the presence of Pleuroplax fedcatus, 

 Oracanthus armigerus, and Ccelacanthus Abdenensis, reminds us at once of that of the 

 Abden " Bone Bed" at Kinghorn, in Fife, though at a considerably higher horizon, for 

 the Fifeshire bed is placed by Sir A. Geikie near the top of the Calciferous Sandstones, 

 so that we have consequently the whole of the Lower Limestone Group between. It is 

 clear that we have here another instance of the recurrence of similar forms under similar 



