^AR 5 1221 



P^ebruiiry, 1921. The Irish Naturalist. 17 



NOTES ON SOME IRISH ENTOMOSTRACA, 



BY ROBERT GURNEY, M.A. 



The following notes on Entomostraca are the result of a 

 week's stay at Malahide (Co. Dublin) at the end of September, 

 1920. During this time I paid visits to Howth and to 

 Newbridge, and have therefore arranged these notes under 

 the heading of these localities in order to brin;s: into 

 prominence the difference in the conditions investigated. 



I. Malahide. 



There is almost an entire absence of fresh-water pools 

 in the neighbourhood of Malahide, but it is an excellent 

 locality for the study of estuarine species, and two fresh- 

 water species of considerable interest were found. 



In the demesne of Malahide Castle are some fine old 

 Beech trees, and the water collected in hollows at the foot 

 of these trees, or at the junction of branches with the stem 

 was investigated, with the result that in one of them were 

 found a few specimens of Moraria varica (Graeter). This 

 is a Copepod resembling in many respects M. arhoricola 

 Scourfieid, which was discovered by Mr. Scourfield in 

 similar situations in Hornbeams and Beeches in Epping 

 Forest, and has since been found to be common in Beech 

 tree holes in the New Forest ; but it is a smaller species, 

 and quite distinct. It was originally found by Graeter in 

 caves in Switzerland, but has also been taken by him and 

 by Chappuis in rotten wood, and by Mr. Scourfield in a 

 tree-hole in Epping " Lower Forest. It is probably 

 therefore a true woodland species. Its occurrence at 

 Malahide seems to me to indicate that the Beech wood 

 "•here is a relic of a once more extensive forest. Other holes 

 in these trees were either altogether barren or contained 

 no Morarias, but in two of them the following species were 

 found : — - 



