230 The hish Naturalist. October, 



this end in view the drift on the northern slope of the Dublin 

 hills has been examined, especially between 400 and 800 feet 

 above sea level, and all sections carefully searched for shells. 



In most of the sections examined the results were extremely 

 meagre, percolating water having reduced the shells to such a 

 chalky condition as to render determination of species a 

 matter of great difficulty, and only from localities specially 

 protected were any satisfactory results obtained. Out of over 

 a dozen sections — scattered over the northern slope of the 

 Dublin hills, from Ballyedmonduff on the east to Glenasmole 

 on the west — the following four yield the best results : — 



The first is a large pit, 100 yards north of the Glendoo Wood, 

 on the road leading from Rockbrook to Glencullen. This pit, 

 850 feet above sea level, is composed of roughly stratified 

 sand and gravel — chiefly limestone, but containing granite, 

 sandstone, mica-schist, and Chalk flints. The shells found 

 here were very chalky, breaking when touched, but the follow- 

 ing species were made out : — 



LaMEIvWBRANCHIATA : 



Pecten opercularis, Linn. Astarte borealis, Chem. 



Cardium tuberculatum, Linn. A. sulcata. Da Costa. 

 C. norvegicum, Spreng. Artemis exoleta, Linn. 



Of these Astarte dorea/zs is Q.t present confined to Arctic and 

 Scandinavian seas. 



The second locality consists of two large pits just outside 

 the entrance gate of Larch Hill demesne. This demesne is 

 situated at the entrance to the glen formed by the slopes of 

 Kilmashoguc Hill and Tibradden Mountain, and known as 

 Kelly's Glen. The section is a very striking one, and merits 

 a detailed description. The beds composing the upper pit, 

 650 feet above sea-level, occur in the following ascending 

 order: — A bed 18 feet thick, consisting of large granite 

 boulders, limestone pebbles, and granitic sand ; many of the 

 granite boulders measure as much as 20 x 9 x 9 inches, and 

 form a quite unique feature in the composition of the bed ; 

 smaller blocks of basalt, conglomerate, sandstone, white 

 quartz, Chalk flints, and mica-schist also occur. From this 

 bed, which shows only the very roughest signs of stratifica- 

 tion, forty species of moUusca and one species of cirripede 



