254 Proceedings of the Royal Physical Society. 



very rarely met with. By far the most abundant relics are 

 the caudal shields, or pygidia, which are sometimes found 

 two or three lying together on one small piece of shale. 

 The head is of rarer occurrence ; it is sometimes found en- 

 tire, but very frequently disjointed, the glabella, or central 

 part, lying apart from the two lateral cephalic shields. Of 

 entire trilobites I found one very good specimen (in the ex- 

 tended position) at Wilkieston, and two doubled or rolled 

 up (after the manner of certain Oniscidce when alarmed). 

 Mr Walker, of the University Museum, St Andrews, showed 

 me also a very good specimen of the entire animal extended, 

 which he obtained at Ladeddie. 



III. Note on the Exposure of the Liberton Old Red Sandstone Conglome- 

 rate Bed, in a Quarry recently opened near the Grange House, New- 

 ington. By Andrew Taylor, Esq. 



The existence of the conglomerate, only visible for a few 

 yards at Liberton Brae, and sinking to the E.S.E. at about 

 35°, was noted, so far back as 1839, by Cunningham, in his 

 prize essay on the Geology of the Lothians. In the excellent 

 descriptive catalogue of the rock specimens in the Jermyn 

 Street Museum, Mr Geikie catalogues this rock as a cal- 

 careous conglomerate; being one of the passage beds between 

 the Old Eed Sandstone and Lower Carboniferous series ; the 

 basis being stated to be a calcareous sand, with the pebbles 

 generally well rounded, and consisting partly of a compact, 

 cherty limestone, partly of different felstones, and sometimes 

 of various gray micaceous grits. The stratigraphical import- 

 ance of this bed in our local geology has likewise been duly 

 recognised in the recently published geological survey map 

 of the district ; in which it has a distinctive colour and boun- 

 dary assigned to it, which is made to terminate at the margin 

 of the great fault, marked as running from the northern base 

 of the Pentland range to near Wester Duddingston. The 

 strata north of this fault-line, and on which Newington with 

 the rest of the city is built, are, on the other hand, pectorially 

 distinguished as decidedly Lower Carboniferous, and beneath 

 the horizon of the Burdiehouse limestone. In the field to the 

 west of that section of the Lover s Loan which runs past the 



