382 Proceedings of the British Association. 



and it was remarked that this paper was one of the advantages 

 derived from the recommendation made to Professor Phillips by 

 the British Association. 



The Rev. Sydney Smith exhibited a specimen, belonging to 

 Mr Fox, of an Echinus, from the mountain limestone of the 

 county of Kildare. 



After the meeting, the members proceeded to the Ordnance 

 Survey Office, Phoenix Park, where they had an opportunity of 

 examining every part of that splendid establishment, and had 

 the advantage of the explanations of Colonel Colby, and the 

 other officers engaged in the survey. 



Wednesday, 12th August. — A copy of the ordnance survey of 

 the parish of Templemore, presented by Colonel Colby, was laid 

 before the Section. 



5. Lieutenant Stothed described a small isolated patch of gra- 

 nite in the county of Cavan, surrounded by transition and se- 

 condary rocks. The effects of this rock on the greywacke schist 

 near it is such as is usually noticed, the schist passing through 

 several stages of induration, and ultimately assuming the cha- 

 racter of quartz rock. The occurrence of this low isolated 

 patch so far removed from the great granitic masses of Down, 

 of Galway, or indeed of any other part of Ireland, is in itself 

 interesting and peculiarly important, as it seems to explain many 

 of the appearances of the interesting tracts of schist, such as 

 their broken and unconnected state in low distinct knolls, and 

 the appearance of undulations they so often exhibit. 



6. Mr Griffith concluded his observations in illustration of 

 his geological map, by describing the nature, distribution, and 

 mode of occurrence of the various unstratified rocks which are met 

 with in Ireland. He spoke first of the granite districts. The 

 granite district of Dublin and Wicklow is fifty miles from north 

 to south, and eleven in breadth. The district of the Morne 

 Mountains in Down is characterized by the rocks contain- 

 ing much hornblende, whereas there is none in the Wicklow 

 rocks. A transition may be observed from granite to sienite. 

 The district of Down contains no mica slate, and is in this re- 

 spect different from Wicklow. Beryls and topazes occur in 

 Down, and beryls have also been found in Wicklow. The 

 strata of Down run N. E. and S. W., and this direction is not 



