292 On Shells and Corah in a Conglomerate at Malvern. 



a foot or only a few inches in thickness against the trap. In 

 the intervals of these pebbles were partial admixtures of ar- 

 gillaceous shale, abundance of shells, and smaller chips and 

 fragments of stone, more or less stained brown, in the same 

 manner as commonly happens in shelly cavities in other con- 

 glomerates and sandstones far removed from the trap. Ex- 

 terior to this very pebbly mass, the shells were equally nume- 

 rous, but the rock fragments amongst which they lay were 

 generally angular, appearing just as if they had fallen from a 

 cliff upon a pebbly beach, and received into their interstices 

 abundance of shells and sand drifted by the water. 



The degree ofjirmness of the shelly masses thus examined 

 in situ, is less on an average than that of the loose pieces on 

 the hill slopes which were first observed ; these latter being 

 the hardest portions which best withstood destroying agencies. 



The shells, corals and encrinites, are commonly represented 

 by casts and moulds, but a few specimens have occurred of 

 Turbinolopsis, with the calcareous substance entirely pre- 

 served. 



The pebbles and fragments of stone mixed with the shells 

 are of the same nature as the rocks immediately adjacent and 

 composing the neighbouring hills; that is to say, characteristic 

 compounds and segregations of hornblende, felspar, quartz, 

 and mica, in great variety. The whole mass is stained by fer- 

 ruginous admixtures, and at a small distance looks like some 

 of the dark trap of the hills with which it is in contact. What 

 may be its degree of induration at a considerable depth is 

 unknown, the situation allowing only of an exploration to the 

 depth of a few feet. 



The just inference from the occurrence of the shelly con- 

 glomerate thus briefly described, appears to be that the sie- 

 nitic and other associated rocks of the northern portion of 

 the Malvern hills were accumulated and indurated previous 

 to the aggregation of the lower portions of the Caradoc sand- 

 stone series; and that they were, with the whole Silurian series, 

 raised in a solid state. 



In harmony with this conclusion, is the abundance of frag- 

 ments and disintegrated grains of the Malvern rocks in other 

 conglomerates (not shelly) of the Caradoc series, about the 

 north end of the chain, examined by Sir H. T. De la Beche 

 and myself. Even in Ankerdine hill, eight miles north of 

 Malvern, fragments of the sienitic rocks were observed in the 

 Caradoc sandstone by Capt. James, R.E., and myself; and 

 the conglomerate of May hill yielded similar results to Sir 

 H. T. De la Beche. 



Observations of this nature, combined with accurate sur- 



