Geological Society of London. 333 



vertebra of elongated form, regarded as indicating a new genus and 

 species, named Spondi/Iosaurus gracilis. Of Pterodactyls there are 

 but few remains ; but these certainly represent two genera. The 

 author only describes one species, to which he gives the name of 

 Ornithochirus Bunzeli. There are, in all, probably ten genera of 

 Dinosaurs and five genera of other groups, making fifteen in all. 



The paper was supplemented by a note by Prof. Suess on the 

 geological relations of the beds at Wiener Neustadt to those of the 

 Grosau vallej% in which he comes to the conclusion that they are 

 older than the true Turonian deposits, and especially older than the 

 zone of Hippurites cornu vaccinum. 



2. " On the Basement-beds of the Cambrian in Anglesey." By 

 Prof. T. McKenny Hughes, M.A., F.G.S. 



In this paper the author first pointed out that there was in 

 Anglesey: — (1) An upper slaty group, in which he had fixed two 

 life zones, which showed that the series belonged to the Silurian 

 (Sedgwick's classification), and (2) a lower group of slates and sand- 

 stones in which Arenig fossils had been found in several localities, 

 and Tremadoc had been less clearly I'eeognized, while by the cor- 

 rection of the determination of a species of Orthis there was now a 

 suspicion of even Menevian forms. These all rested upon the Base- 

 ment-beds of the Cambrian, of which the paper chiefly treated. 

 Tliey were made up of conglomerates, grits, and sandstones, with 

 Annelids and Facoids, 



Tlie Basement-beds varied in thickness and character, according 

 to the drift of currents along the Pre-cambrian shore and the material 

 of the underlying rocks. Near Penlon, where they rested on a 

 quartz-felspar rock, they consisted chiefly of a quartz-grit and con- 

 glomerate, almost exactly like that of Twt Hill. Near Llanerchy- 

 medd, where there was a mass of greenish schistose rock succeeding 

 the Dimetian, the Cambrian Basement-bed contained a large number 

 of fragments of that rock, certain bands being chiefly composed of it. 

 Near Bryngwallen, where the underlying Arch^an consisted of 

 gneissic rocks, the Cambrian Basement-beds were made up of quartz 

 conglomerate. Tracing it still further to the S.W., he found bosses 

 of conglomerate among the sand dunes of Cymmeran Bay, full of 

 fragments of green schistose rock, like that of Bangor, and telling of 

 the further development of Pebidian at the S.W. end of the Anglesey 

 axis. In several localities these conglomerates were associated with 

 and passed into fossiliferous grits and sandstones. He exhibited 

 slices of the more important rocks, which he showed confirmed the 

 results arrived at from other evidence. He pointed out that the 

 observations now made confirmed the views he had expressed on a 

 former occasion with regard to the Basement-beds of the Cambrian 

 between Caernarvon and Bangor, where the deposits which rested 

 upon the granitoid rocks of Twt Hill were either a kiiad of arkose 

 or chiefly composed of quartz with a few pieces of mica-schist and 

 jasper ; but as he followed them a few miles to the N.E., he found 

 that the quartz had got pounded into smaller grains, and the larger 

 pebbles were chiefly of felsite, which here formed the shore, while 



