G. H. Kinahan — Devon, Cornwall, and Galway. 313 



valleys among the Cork tills ; for at present, as a rule, they are des- 

 titute of moraine drift accumulations, it only being found on the 

 flats, ^ at the mouths of the valleys. 



It has now been shown it is possible, if not probable, that ice was 

 a more potent agent than meteoric abrasion during the formation of 

 the Devonshire valleys, but it has still to be considered whether the 

 sea could have exerted any influence. My acquaintance with Devon- 

 shire is so limited that I may not be justified in offering an opinion ; 

 however, as it has been shown there is an analogy between the 

 valleys of that country and those of West Cork and G-alway, it may 

 be suggested, that if marine denudation can be proved to have 

 assisted in forming the features of these counties, it probably also 

 helped during the formation of the present surface of Devonshire. 



In the west of the Co. Cork, also in Kerry, there are deep semi- 

 circular valleys or combes cut into the sides of the hills, remark- 

 able on account of the floors of the different sets being on nearly 

 similar horizons. In these counties the combes are nearly always 

 occupied by lakes in " rock basins," and, as Professor Kamsay sug- 

 gests, it is highly probable these basins were scooped out by ice ; 

 moreover, it is more than probable that subsequently the combes 

 were carved out by marine denudation, not only because their floors 

 are on regular systems of horizons, but also on account of these 

 levels agreeing with those of the combes and terraces of the other 

 hill-groups in Ireland hundreds of miles apart. In West Cork, as 

 just suggested, the features of the oombes are supposed to have 

 been modified by ice action, apparently because the rocks were not 

 sufficiently tenacious to be capable of offering much resistance to 

 that denudant. This, however, was not the case among all the hills 

 of Yar-connaught, for although the granite and Silurian ground in 

 places seems to have suffered greatly from ice-action, yet in many 

 places among the hills formed of the metamorphic rocks, the terraces 

 ■ and combes (or lugs'^ as they are called in that country) are appa- 

 rently in nearly a similar state as when the sea retreated from them, 

 having usually a slightly sloping floor, and the lugs rarely, if ever, 

 containing a lake. The accompanying Fig. 3. represents some of 

 these lugs, while others and terraces are seen in Fig. 1. The floors 

 of these lugs, the shelves or terraces cut in the slopes of the hills, 

 and the maums^ or connecting gaps, here as well as in West Cork, 

 are on different systems of levels, seemingly proving that each 

 system was formed by one and the same denudant, very universal in 

 its operation, and similar to no other force at work during the 

 present age save marine action. That these terraces, combes, lugs, 



1 A letter from Mr. G. "W. Ormerod, printed at page 40 of the Geological Maga- 

 zine for 1869, notices the traces of glacial action in South Devon, and states that 

 probably for the words " Old Gravels,'' used in his paper " On the Geology of the 

 valleys of the upper part of the river Teign and its feeders " (Quart. Journ., vol. 

 xxiii., page 418), the -word " Moraines " should be substituted. 



2 luff, a valley or gloomy depression among hills. 



3 Maum or Mam, mountain pass, or connecting gap through a mountain ridge, 

 derived from Mann {Mawn), the inside part or hollow of the hand. (See article on 

 Formation of Ravines, by author, in Geol. Mag. Vol. VI. 1869, p. 406.) 



