145 



subject of many important memoirs, one section of Geologists 

 regarding these beds as the highest member of the Trias, another 

 as the lowest of the Lias. They are probably intermediate 

 between the two, and contemporaneous with the Kossener scMchten 

 or Upper St. Cassion beds of Eschek and Merian. This gToup is 

 finely exposed at Garden CHff, on the Severn ; and our members 

 are famiHar with the locality, both from personal examination, 

 and from the fine detailed section given thereof by my friend 

 R. Etheeidge, Esq., E.G.S., in the volume of our Transactions 

 for 1864, p. 218, to which I must refer for further details. In 

 many other localities the group is well developed; and wherever 

 the junction of the Lias and the Keuper is exposed in situ, in 

 most cases will the Avicula contorta beds be found interposed 

 between them ; although only of about 35 feet in thickness in 

 England, these beds represent a most important series of strata 

 on the continent of Europe. 



Having examined the Avicula contorta series with much care 

 in several localities in the counties of Gloucester, Somerset, 

 Warwick, Dorset, and Glamorgan, I can state that Corals are 

 extremely rare in the cream-coloured Limestones of the series, 

 a few stunted Montlivaltia having been the only Actinozoa I 

 have found, and these were indeterminable from their imperfect 

 preservation. 



Tn Lombardy, however, the Abbe Antoine Stoppani has 

 discovered a remarkable Coral fauna in the Azzarola beds, and 

 the fossils therefrom he has figured and described in his memoir ® 

 on that formation. The Madrej)ore bed, so called by the author, 

 is seen above the Azzarola beds, with Cardium Rhceticum, 

 Myophoria inflata, Mytilus Psilonoti, and Avicula contorta, all 

 leading fossils of the Avicula contorta group, wherever the 

 succession of the rocks can be made out. The Abbe Stoppani 

 has hkewise described the Coral bed as occurring below and in 

 the midst of the Azzarola beds, and forming a dense layer, 

 from 8 to 10 yards in thickness, the prevailing species in this 

 ancient reef being a branching Coral, Rhabdophyllia Langohardica, 

 Stop., with three other congeneric forms, together with species 

 of Montlivaltia, Stylina, and Thamnastrwa. 



" A. Stoppant, Monogr. rles foss. rle 1' Azzarola. 



