l66 The Irish Naturalist. August, 



valueless if the nest itself is too freely exposed to view. 

 In view of this consideration, the concealing value of the 

 dome, to which so much importance has been attached, is 

 seen to be really very limited — though it may suffice against 

 certain t}pes of enemies, including reptiles of low brain- 

 power, and these may at one time have been the only type 

 that needed to be considered, while they may still be a 

 formidable factor to birds breeding in reptile-infested 

 countries. Looking to our own land, and to the present day, I 

 know of no more useful purpose that the domed nest is 

 qualified to serve than that of enabling a bird to rear a 

 larger famih' than it could rear in an open nest of the ordinary 

 pattern. 



Ballyhylaiid, Co. Wexford. 



DUBLIN MARINE BIOLOGICAL COMMITTEE 



REPORT FOR 1908. 



WITH SPECIAL NOTES ON THE MOLI.USCA. 

 BY NATHANIEL COLGAN, M.R.I.A. 



During the last year the Committee continued its dredging 

 and shore-collecting operations along the County Dublin 

 coasts with considerable assiduity and with a fair measure of 

 success, so far at least as the department of Mollusca is 

 concerned. The dredgings were more exclusively confined 

 to the inshore waters than in the preceding year, none of the 

 trips extending farther seaward thrin a half mile eastward of 

 the outermost of the Skerries islands on the north, or the 

 same distance eastward of the Muglins rock on the south. 

 Repeated visits were made at different seasons to some of the 

 richer grounds, and altogether ten dredging trips were made 

 by the Committee, the earliest on the 22nd April and the latest 

 on the nth November. In addition to the Committee trips 

 proper, the writer of these notes made a couple of dredgings 

 on his own account during a holiday passed at Skerries in 

 July last. The results of these twelve dredging trips, and of 

 some shore-collecting done by the writer at Skerries and at 

 Bullock are summarised in this report. In spite of the usual 



