BRITISH ASSOCIATION MEETING. 



311 



remains from Street, now in the British and other museums, were collected 

 from this zone, together with the remarkable Flesiosaunis megacephalus 

 (Stritch), of which only two specimens were known, the one contained in the 

 Bristol Museum, and the other in the Warwick Museum. 



The zone of Ammonites aiiguJatus (Schoth.), which forms so important a sub- 

 division of the Lower Lias of France and Belgium, and contains in these coun- 

 ties so rich a fauna, is represented in England by a few characteristic ammonites 

 only, it is exposed in the Harbury cuttmg near Warwick, from whence most of 

 our specimens have been obtained. 



2nd. The zone of Ammonites BucUandi is well exposed in the Church cliff 

 of Lyme Regis, in the Harburg cutting, in various sections in Somersetshire, 

 as at Saltford, and near Bath, and in Gloucestershire and Glamorganshire. 

 This zone contains many species of Ammonites, as A. Bucklandi, A. rotiformis, 



A. Greenouglii, and A. tortilis, and A. Conj/beari, with Lima gigcmtea^ and Gry- 

 plma arcuatu. 



3i'd. The zone of Ammonites Timieri contains many of the Lyme Regis 

 saurians, as Ichthyosaurus platyodon, associated with Am. semicostattis (Y. and 



B. ), and A. Bownardi, and Fentacmms tuliercidatus (Mill). 



4th. The zone of Ammonites olitusus is best shown at Lyme Begis, between 

 Broad Ledge and Cornstone ledges, near Charm outh. Its beds are very 

 fossiliferous ; here are found Am. obtusus, A. stellaris, A. planicosta, and A. 

 Dudressieri. This zone was exposed in Gloucestershire, in the cuttings of the 

 Bristol and Birmingham railway, and at Bredon, in Worcestershire, a large 

 assemblage of its cephalopods was found. 



5th. The zone of Ammonites oxynottis is found near Black Venn, at Lyme, 

 and in the vale of Gloucester, Am. oxynotus, A. bifer, A. lacunatus, lie in this 

 zone. 



6th. The zone of Ammonites raricostatus is well seen at Lyme Begis, in the 

 vale of Gloucester, and at Bobin Hood's bay, in Yorkshire. The beds belong- 

 ing to this and the preceding zone are very ferruginous, and many of their 

 fossils are preserved with difiiculty. 



Hippopodium ponderosum, Gryphaa obliquata, and a thin band of corals 

 occupy the upper beds. With these are associated many other moUusca and 

 Fentacmms scalaris. Am. armatus, A. dentinodus, and A. varicostatus lie toge- 

 ther in the lower beds of the zone. 



ON THE METAMOEPHIC EOCKS OF THE NOETH OP lEELAND. 

 By Peopessou Haekxess, F.E.S. 



On referring to the geological map of Ireland, by Sir Richard Griffiths, Bart., 

 it T^dll be seen that a large area in the north of Ireland is occupied by rocks of 

 a metamorphic nature. These rocks, weU exhibited in the county of Donegal, 

 are composed of mica-schists and quartz-rocks, which are seen occupying well- 

 marked districts in this part of Ireland. These mica-schists and quartz-rocks 

 are subject to great contortions, and have a prevailing south-east dip in the 

 north of Ireland. The relative position which these rocks bear to each other 

 is w^ell seen in a section of about twenty miles along the coast, between Inish- 

 oweu head and Mulin head, the extreme north point of Ireland. Although the 

 mica-schists and quartz-rocks are several times repeated in this section, the 

 result of great flexures and contortions, the section shows that quartz-rocks 

 are the oldest rocks of this portion of Ireland, and that they are conformably 

 overlaid by the mica-schists. An anticlinal axes occurs among these meta- 

 morphic rocks a little south of Mulin liead, and on the north side of this axis, 



