382 Reports and Proceedings — Geological Society of London. 



4. " Additions to the Fauna of the OJenellus-zone of the North- 

 west Highlands." By B. N. Peach, Esq., F.R.S., F.G.S. (Com- 

 municated by permission of the Director- General Greological Survey.) 



New material obtained by the Officers of the Geological Survey 

 has been placed in the author's hands, and as a result he is enabled 

 to add information concerning the species of Olenellus previously 

 described by him (0. Lapioorthi) ; he also describes a new variety 

 of this species, three new species of the genus, a new subgenus of 

 Olenellus, and a form provisionally referred to Bathynotus. 



A study of the remains described in the paper make it probable 

 that the dispersal of the Olenellids was from the Old World towards 

 the New. 



5. "Questions relating to the Formation of Coal-Seams, including 

 a New Theory of them ; suggested by Field and other Observations 

 made during the past decade on both sides of the Atlantic." By 

 W. S. Gresley, Esq., F.G.S. 



A number of new facts are described, and the bearing of these 

 and of previously recorded facts upon the origin of coal is discussed, 

 special reference being made to the Pittsburgh Coal. The author 

 lays stress on the stratification of coal, the sharp line of demarcation 

 between coal and underclays, the character of the plants in the 

 underclays and their asserted root-nature, the existence of partings 

 in such seams as the Pittsburgh Coal, which partings sometimes 

 contain Anthracosia, and really separate the coal into distinct seams. 

 He describes the occurrence of " rods " of vegetable origin whose 

 exact nature is not known, which, with ferns, he suggests con- 

 tributed largely to the formation of some coals. He maintains that 

 the evidence points to the formation of coal on the floor of an 

 expanse of water, by vegetable matter sinking down from floating 

 " islands " of vegetation, which may have been of very large size, 

 and enumerates cases of such "islands" or "rafts" of vegetation 

 which have been described as existing in modern times. 



6. "Observations regarding the Occurrence of Anthracite generally, 

 with a New Theory as to its Origin." By W. S. Gresley, Esq., F.G.S. 



After discussing Dr. J. J. Stevenson's theory of the origin of 

 anthracite, the author desci"ibes the nature and mode of occurrence 

 of the anthracites of Pennsylvania, and gives his reasons for con- 

 cluding that the de-bituminization of coal was not produced by 

 dynamic metamorphism during mountain-building but rather by 

 previously applied hydrotliermal action. 



7. "The Igneous Rocks of the Neighbourhood of Builth." By 

 Henry Woods, Esq., M.A., F.G.S. 



In south-west Radnorshire (just north of Builth) there is an area 

 of Ordovician and associated igneous rocks, surrounded on all sides, 

 except the north-west, by Sihu'ian beds; this is shown on Sheet 56 

 S.W. and S.E. of the Geological Survey map, and was described by 

 Murchison. In this paper the author gives a map of the southern 

 half of this area, and a description of the igneous rocks — andesites, 

 andesitic ash, rhyolites, diabase-porphyrite, and diabase. The 

 diabase-porphyrite is intrusive in the andesite, and the diabase in 

 the Llandeilo Shales. The andesitic ash rests on the andesite, and 



