Prof. C. Lapworth on the Girvan Sucession. 147 



(21. laevigata and 21. Goldfussi), Hinnites, Monotis, Avicula (A. 

 Broiiiu). Myacites, Bissoa, and many others difficult to determine. 



i; The places where the fossils have been found are the following : — 

 on the southern slopes of the Sierra de Gador, in the Bambla del 

 Caiiuelo ; midway on the road from Felix to Alarchal ; and in the 

 place named La Solana del Fondon, to the left of the river Andarax, 

 following the track between the mine Sebastopol and the town of 

 El Fondon. a JoAQTOr Goxzaxo t Xaviee." 



2. " The Girvan Succession. — Part I. Stratigraphical." By 

 Charles Lapworth, Esq., F.G.S., Professor of Geology in the Alason 

 Science College, Bh-mingham. 



The Lower Palaeozoic rocks of the neighbourhood of Girvan, in 

 the south of Ayrshire, have long been famous for the remarkable 

 variety of their petrological features, and for the abundance and 

 beauty of their organic remains ; but the strata are so intermingled 

 and confused by faults, folds, and inversions, that it has hitherto 

 been found impossible to give a satisfactory account of the geological 

 structure of the region. 



The most remarkable formation in this Girvan area is a massive 

 boulder-conglomerate, several hundreds of feet in thickness, which 

 forms the high ground of Benan Hill, and ranges throughout the 

 district from end to end. Employing this formation as a defiuite 

 horizon of reference, the author showed, by numerous plans and 

 sections, that it was possible for the geologist to work out the 

 natural order of the strata, both above and below this horizon, and 

 to construct a complete stratigraj>hical and palaeontological scheme 

 of the entire Girvan succession. This succession is composed of the 

 following members, arranged in descending order : — 



(I.) Eppee Gibyah Eoces. 

 (D.) Daieet Seeees (1500 to 2000 feet), including the 



(3) Straiton Group, consisting of grey flags, shales, and grits, 

 with BeyricMa Klcedeni, Cardiola, &c. 



(2) Bargany Group, of pale flagstones, shales, and mudstones, 

 with Retiolites Geinitzianus, Cyrtograptus Grayi, &c. 



(1) Penkill Group, of purple mudstones, grey flags, and grey- 



wackes, with Crossopodia, Protovirgularia, &c. 



(C.) Xewlases Seeees (1000 to 1500 feet), embracing the 



(3) Camregan Group &c, of yellow thick-bedded grits and 



dark shales, with a band of calcareous rock ; abounding in 

 Pentamerus ohlongus,Atrypa reticularis, Rastrites ma^imus, 

 and 2Ionograptus Sedgtmckii. 



(2) Saugh-HiV. Group, composed of alternations of coarse 



pebbly grit and zones of grey and black shales, with a 

 coarse conglomerate at the base. Its commonest fossils 

 are Striddo.iulinia lens, Pentamerus oblongus, Favositea 

 gothlandicus, 21oiwgraptus leptoiheca, &c 

 (1) MuMoch-HM Group, formed of shellv sandstones underlain 

 L2 



