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Monday, bth March 1855. 



KiGHT Rev. Bishop TERROT, V.P., in the Chair. 



The following Communications were read : — 



] . On Annelid Tracks in the Exploration of the Millstone 

 Grits in the South-west of the County of Clare. By 

 Robert Harkness, Esq., FR.S.E., F.G.S., Professor of 

 Geology, Queen's College, Cork. 



The author remarks that the existence of Annelida during the 

 Palfeozoic formations is manifested in two conditions. In the one, 

 we have the shelly envelope which invests the order Tubicola, in the 

 form of Seapolites ; and in the other, the tracks of the oi'ders Abran- 

 chia and Dorsi-branchiata are found impressed on deposits which 

 were, at one time, in a sufficiently soft state to receive the impres- 

 sions of the wanderings of these animals. 



Among the strata which have hitherto afforded annelid tracks, 

 those which, in the county of Clare, represent a portion of the equi- 

 valents of the Millstone Grit, contain such tracks, in their most per- 

 fect state of preservation in great abundance ; and these strata also 

 furnish evidence concerning the circumstances which prevailed during 

 their deposition. 



The locality of these strata is the neighbourhood of Kilrush, on 

 the banks of the Shannon, in the southern portion of the county. 

 Here the deposits consist of strata which have a flaggy character ; 

 and these have been extensively wrought at Money Point, about four 

 miles east from Kilrush, and they supply the flags which are com- 

 monly used in the towns of the south of Ireland. The beds vary 

 somewhat in their nature, and with this circumstance they present 

 different phenomena. 



The annelid tracks occur in three conditions. When they are in 

 their most perfect state, in the faces of the higher flags, which are 

 of a greenish gray colour, they have the form of meandering tracks, 

 about half an inch across, and their margins crenated. A distinct 

 raised Ime traverses the centre of these tracks, and the interval be- 

 tween this line and the crenations is marked by a succession of other 



