206 THE ENTOMOLOGIST. 



an upward movement commences, sheet after sheet of lime- 

 stone rock is swept away as it approaches the surface and 

 comes under the wearing action of the waves, and finally old 

 Hovvth again beholds the sun, and is peopled with new 

 forms of life.* 



It seems, however, to have met with only a cold reception 

 on its second advent, having apparently emerged during the 

 glacial period : thick accumulations of drift, sand and clay 

 may be seen in the cliffs on the northern shore, and the 

 rocks of the higher portions of the hill are grooved and 

 polished, no doubt by the action of the icebergs which 

 grounded on the rising shores. 



Along the southern cliffs, a hundred feet above the sea- 

 level, an old sea-beach, probably of the glacial period, may- 

 be traced ; it is loaded with shells, almost in a recent con- 

 dition. 



From the elevated central portion of the hill the view is 

 magnificent : on a clear day the eye ranges from the Mourne 

 mountains, far to the north in the County Down, to the 

 heights of Snaefell in the Isle of Man; thence to Snowdon 

 on the distant eastern horizon ; to the south, Wicklow Head ; 

 and the picturesque outline of the Wicklow mountains com- 

 pletes the circle to Bray Head, frowning across the broad 

 expanse of Dublin Bay. 



About three hundred species of Lepidoptera are known to 

 occur at Howth, but there is no reason to think that this 

 comprises anything near the total number which might be 

 found, as, except during the three summer months, little col- 

 lecting has been attempted, and two of the most productive 

 methods for the capture of Lepidoptera (sugar and light) can 

 only be tried by stealth. The cliffs are the chosen parade- 

 ground of the coastguard, and the hapless Entomologist, 

 upon whom a big Irishman, armed with cutlass and pistols, 

 pounces from behind a rock, finds it as useless to argue with 



* " Howtli Hill, Laving been an island in tlie carboniferous sea, was 

 surrounded by beds of limestone deposited against its shores, higher and 

 higher beds touching those shores as the isLmd sank in the sea, until it 

 was possibly entirely entombed in the limestone. It has since been re- 

 elevated and partially exhumed by denudation, but there is no evidence to 

 show that the contour-line, now at the sea-level, was the original base of 

 the old island." — /. B. Jukes, Explanations of the Geological Survey of 

 Ireland. 



