WiaCiiir — fJmncii/hcriu : .1 New Cone has tracan Genus. ty.'i 



variation sets in, and the place of tlie niaiine band is oucujjied by a massive 

 sandstone, now knuw n as the Woodview Sandstone. The strata on the same 

 horizon in the Ardra bore show a condition internieiliate between these two 

 phases of sedimentation, and probably represent a transition from deltaic 

 to marine conditions. The fleck-rock is present and shows the very 

 characteristic flecking or mottling, but there is a complete absence of marine 

 fossils. Moreover, the bed is much divided up and interleaved with sandy 

 shales and sandstones, and the laminae of the fleck-rock have a much more 

 shaly structure than it possesses in places where it is more typically 

 developed. 



The fossils described in the present paper do not occur actually in the 

 fleck-rock, but in the sliichtly sandy shales about eiglit or nine feet above its 

 upper layer. These shales may be equivalent either to the marine shales 

 normally found above the fleck-rock in the districts lying to the east and 

 south, or to the non-fossiliferous shales above these latter. Purther, as regards 

 correlation to the west, in the Skehana area, they may be equivalent either to 

 the upper portion of the Woodview Sandstone or to the thin band of shales 

 which occurs between the Woodview Sandstone and the Skehana seam. It is 

 not possible, on account of the great lateral variation of the beds, to attain 

 any greater precision than this; but, as regards restoring the conditions under 

 which these remarkable animals existed, we can with fair confidence make the 

 following statement : — • 



Just before the establishment of the conditions which made the existence 

 of the Estherian fauna possible, Ardra w-as on the edge of a sand-bank or delta 

 which lay to the north-west, while to the east and south at no great distance 

 lay open sea or estuary. Sometimes the sand was pushed east over the site, 

 and sometimes the sea with the organisms, whatever they were, that caused 

 the decking, crept west. Then the sand finally failed to reach the site, the 

 sea no longer encroached, and the mud-stones in which the fossils are found 

 were laid down. At this period the sand-bank was probably still in progress 

 of formation a short distance to the north-west, and the sea with its marine 

 fauna lay to the south and east. Finally, the muddy conditions led up to 

 the growth of the Skehana coal-seam. This seam attains its ma.ximum 

 development in the area to the north-west, and appears to be thinning 

 somewhat at Ardra ; but the horizon on which it lies is marked by a thin 

 coal-rod extending far into the previously marine area to the south and west. 



Although shells referable to some small species of Estheria (using the term 

 in the palaeontological sense) are found at various horizons in the strata of 

 the Kilkenny coalfield, yet there is no known case of a fauna equal in 

 abundance and state of preservation to that of the Ardra borehole. One migiit 



