106 NATURAL HISTORY SOCIETY OF DUBLIN. 



The following paper was read : — 



On the Occurrence oe Hymenophyllum Tunbridgense (Smith) in the 

 County of Longford, with a List of Stations of Cystopteris fra- 

 gilis (Bernh.) in the Midland Counties. By F. J. Foot, M. A., 

 F. E. G. S. I., Corresponding Member. 



I am happy to be able to record the occurrence of JTymenophyllum 

 Tunbridgense in the county of Longford. 



Having been lately on a short geological tour in that part of the 

 country, I came across a considerable exposure of conglomerate rocks, 

 forming rather bold crags, on the east side of the road leading from 

 Longford to Ballymahon, about six miles south of the former. It was 

 just at the junction of the townlands of Commock and Curraghmore, on 

 the western extremity of Slieve Ardagh, a low hill of Old Bed Sand- 

 stone, which, rising here from the limestone plain, extends eastwards 

 to the little village of Ardagh. It at once struck me as being a likely 

 spot for Hymenophyllum, and my conjecture proved true ; for, after a 

 short search, I found the plant growing at the foot of a low cliff of con- 

 glomerate, having a western aspect. I only found one tuft, or small 

 mat of it ; indeed, it was raining so heavily at the time, that I was con- 

 tented with establishing the fact of its existence at the place, and did 

 not look for more. 



Further north and north-west, both in the counties of Longford and 

 Roscommon, the Old Bed forms several other hills in the plain, protrud- 

 ing through the low lying and level limestone ground ; and I have no 

 doubt that when the conglomerate or grit rocks crop out in bluffs or 

 crags, as they do here, Hymenophyllum Tunbridgense, and probably H. 

 Wilsoni also, will be found to occur. My colleague, Mr. G. H. Kinahan, 

 tells me that he found Hymenophyllum on every conglomerate crag on 

 the Slieve Aughta hills, in the counties of Clare and Galway. 



These newly recorded stations, in addition to the old and well-known 

 ones of the county of Wicklowj and the mountains in the south-west, 

 give the Hymenophyllum a very extended range in Ireland. Its habitat 

 is always on the older rocks, and particularly those of the Old Bed Sand- . 

 stone. Why is this ? "We do not find it on limestone, because a calca., 

 reous soil is injurious to the welfare of the plant. But why do we not' 

 meet with it on the quartzose grits and sandstones of the Coal measures, 

 which frequently, as in the counties of Cork, Kerry, and Clare, form 

 wild hills, with rugged crags and cliffs, apparently well suited for Hy- 

 menophyllum ? I believe this to be a question intimately connected 

 with the geological history of the country. 



In conclusion, I give a list of the localities where I have observed 

 Cystopteris fragilis in the midland counties : — 



1 . Two miles south-east of Ballymore, county of Westmeath, close 

 to the cross roads near Clare Castle, on the north-west side of the road 

 running south-west from the cross. 



