814 SoLLAS — A Map to show the Distribution of Eskers in Ireland. 



iii. The Bally duff chain. — This is a continuous esker, 1 1 miles in length, with 

 a very regular and steep slope on the northern and a very gentle one on the 

 southern face. 



II. The System of Paksonstown. — This consists of the following chains : — 



1. Killimor chain. 



2. Tynagh chain, and 



3. Duniry chain, converging into 



4. Fairfield chain. 



5. Frankford chain. 



6. Banagher chain. (All in fig. 4.) 



On the west the system commences in three tributary chains, viz. those of 

 Killimor, Tynagh, and Duniry (fig. 4), which rise immediately east of the high 

 ground formed by the northern termination of the Slieve Aughta mountains. 



1. The Killimor chain. — This, about 7 miles long, commences near Dartfield, 

 and runs eastward to its termination in the callows of the Shannon. 



2. The Tynagh chain. — This begins in a series of isolated hillocks, not far 

 from Masonbrook House, and runs past the village of Tynagh, to join the 

 Duniry chain, some little distance west of Fairfield. 



3. The Duniry chain. — This begins in separate hillocks about the source of the 

 Duniry river ; it receives the Tynagh chain, and is continued eastward as — 



4. The Fairfield chain. — This approaches closely to the chain of Killimor, but 

 without actually reaching it, and ends just on the borders of the alluvial flats of 

 the Shannon. 



The preceding chains, which may be collectively designated the sub-system of 

 Portumna, are represented on sheet 116 of the one-inch map of the Geological 

 Survey, and are described in the accompanying Memoir by Mr. Gr. H. Kinahan. 

 They present us with one of the most beautiful examples of river-like distribution 

 to be found among the eskers of Ireland. Mr, Kinahan states that numerous 

 large blocks of limestone are perched on some of the eskers of this group ; the 

 largest block recorded measured 12 feet by 9 feet by 4 feet. It lies on the slope 

 of the Killimor chain, near the town of Killimor. 



5. The Frankford chain. — This (fig. 4), which appears to be the natural con- 

 tinuation of the Portumna sub-system just described, is, however, separated from 

 it by the Shannon with its bordering callows. It is fairly continuous, with a 

 length of about 25 miles. N.N.E. of Parsonstown it is narrow and strongly 

 mai'ked, the summit of the ridge being only wide enough, in some places, to 

 admit of a roadway ; its slopes have an angle of from 30 to 35 degrees, and its 



