'642 ME. D. C. EVANS ON THE OEDOVICIAN [Nov. 1906, 



fordwest. Yet their relative position, general character, and fossil- 

 contents render their identification fairly certain. 



The beds to which a Lower Llandovery age has been assigned, 

 being singularly barren, are like beds of that age elsewhere in their 

 very barrenness. I feel convinced that their proper place has been 

 allotted to them, but cannot satisfactorily express the reasons that 

 form the basis of this conviction. 



Some work on the belt of ground that lies to the north of the 

 area now described will, it is believed, throw much light on 

 this matter. 



In conclusion, I desire to state that when this work was in 

 its earlier stages I received much valuable advice from the late 

 Dr. Henry Hicks, F.R.S. I also desire to express my indebtedness 

 to Miss G. L. Elles, D.Sc, who very kindly examined and identified 

 some of my graptolites, and made valuable suggestions as to the age 

 of the rocks from which the graptolites had been collected. 



It is right that I should also express my obligations to those 

 landowners and landholders who very kindly and readily granted 

 me permission to go over their land, and otherwise helped me 

 with the work ; also to many farmers and others who rendered me 

 assistance with pick and spade, and in collecting a large number of 

 fossils. 



EXPLANATION OF PLATE XLVI. 



Map of the Ordovician rocks of Western Carmarthenshire, on the 

 scale of 1 inch to the mile. 



Discussion. 



The Chairman (Mr. A. Steahan) considered that this paper 

 showed evidence of long and careful work in the field. Almost 

 unassisted, the Author had succeeded in identifying the zones and 

 unravelling the structure of a most complicated bit of Ordovician 

 ground. When the officers of the Geological Survey entered the 

 region in 1903, he not only placed all his knowledge at their disposal, 

 but continued his work in close association with them — to their 

 great mutual advantage. Pressure, however, had been put upon 

 him to bring his results before the Geological Society of London, 

 and thus get full credit for his own researches. 



The ground which the Author had examined was partly the same 

 as that described in a paper compiled by Dr. Marr from notes left 

 by the late Mr. Thomas Roberts, and published in the Quarterly 

 Journal in 1893. Eoberts's work, so far as it went, was excellent, 

 but he had made no more than a commencement of his investigation 

 of the district when he died. 



Mr. T. C. Canteill thought that one of the most important points 

 in the paper was the identification of Nemagraptus gracilis in the 

 limestone which, at Mydrim, separates the brown-weathering 

 Dicranograptus-Shales below, from the black Dicranograptus-Shales 



