Fearnsides, Elles, Smith — Palceozoic Rocks of Pomeroy. 107 



may therefore term it the Dimorphograptiis band; and from the fact 

 that almost all the other species of Graptolites it contains range 

 upward rather than downward, we have here decided to group it with 

 those higher beds as the lowest member of the Edenvale beds. It i& 

 about three feet thick, and to us has proved most prolific at its 

 most southerly exposure in the Slate Quarry stream, immediately 

 opposite the road entrance to Edenvale House. The most usual 

 fossils are Dimorphograptus confertus^ D. longissimus^ and Monograptus 

 tenuis. 



The rest of the Edenvale beds possess equally distinctive lithological 

 characters, and are the most readily traceable of all the members 

 of the Little River group. They are a series of dark to light grey 

 shales, mainly unfossiliferous, but with numerous conspicuous darker 

 partings, streaks, and thin bands of Graptolite shale, yielding Climaco- 

 grapti and various narrow forms of Monograptus. They contain 

 much finely divided pyrites, and, unlike the Slate Quarry beds below, 

 are always covered with an ochreous rust or slime during the early 

 stages of weathering, and disintegrating rapidly, pass to a dark 

 ochreous clay paste before they bleach. The total thickness of this 

 division may be about 15 to 20 feet. The most obvious of the 

 Graptolite species are Monograptus tenuis^ M. cyphus, and Clwiaco- 

 graptus rectangular is. 



The Mullaghnaluoyah Beds. 



The Mullaghnabuoyah beds are also well exposed, and are repeated 

 by folding again and again along the bed and banks of the Little Eiver, 

 above the Slate Quarry, and in its northward-flowing tributary, within 

 the Pomeroy demesne. They too, are a series of banded mudstones, 

 and, with the belt of grey flaggy shales in their midst, are 

 probably the thickest of the divisions within the Little River group. 

 A close study of them would probably lead to the adoption of a three- 

 fold division of the series into a lower member, whose lithology is not 

 unlike the upper beds of the Edenvale beds below ; a middle member, 

 unfossiliferous on the whole, consisting of papery shales and thin 

 bedded fissile, gritty flags ; and an upper banded series of blue, almost 

 black, shale. Owing, however, to the difficulty of indicating the 

 excessive folding noticeable at each of the available exposures, such 

 separation has not been attempted upon the map. 



The lowest mudstones, with blacker shale bands, contain a fauna 

 which, except for the presence of Monograptus triangulatus, is- 



