1908. 99 



THE OCCURRENCE OF HIGH-I,EVEE SHELLY DRIFT 

 IN THE KILLAKEE VALLEY, COUNTY DUBLIN. 



BY J. DE W. HINCH. 

 [Read before the Dabliu Naturalists' Field Club, February 18, 1908.] 



The position of the section of shelly drift which I wish to 

 deal with is situated on the Militar}^ Road, running from the 

 Killakee valley to Glencree. On this road a point is reached 

 where the road is joined b}^ that coming from Glendhu, and 

 it is in the right angle that the road makes here that the 

 section occurs. The height above sea-level can be stated 

 with more than usual definiteness^ for the 1,273 f^^t bench- 

 mark of the Ordnance Survey is placed on the road a few feet 

 to the south, and the 1,250 contour line enters the angle 

 mentioned, and runs a few feet from the eastern and northern 

 ^dge. The drift is of a very mixed type, but four kinds may 

 be seen — (i) Boulder-clay, containing man}' erratics of lime- 

 stone and grit, and some granite ; (2) claye}^ sand ; (3) clean 

 fine sand ; (4) a series of w^isps and pockets of rather coarse, 

 gravelly sand. It is in the last of these that the shell frag- 

 ments occur. The pit is an extremely shallow one, not 

 more than six or seven feet at its deepest part, and as a col- 

 lecting ground for shell fragments most unsatisfactory ; 

 indeed, after four visits, I was only able to reckon 27 frag- 

 ments altogether. These are of the usual type of shells 

 collected from gravell}" sand, and so fragmentary that, with 

 three exceptions, it was quite impossible to identify either 

 species or genera— -the exceptions being a rather large (15 mm. 

 long) fragment of Mytilus, an incomplete Tellina balthica^ and 

 a complete valve of Asiarte compressa — the most ubiquitous of 

 the Glacial mollusca. On the road outside are heaps of the 

 pit material awaiting removal, and on the heaps I collected 

 over fifty shell-fragments. These, strictly speaking, should 

 not be used as records, but as the material is from the pit, and 

 as they include Cardiicm edtile 2i\\d Cyprina islandica, I mention 

 them. The erratics in the drift are numerous (the pit is 

 being worked for road metal), and include the following : — 

 Carboniferous limestone in large quantities, granite, chalk 



