189^.] Proceedi7igs of Irish Societies. 2^() 



Not far from the church we come to vSt John's Point and its lighthouse. 

 There is a well-marked difference between the surface geology of the 

 bay south of St. John's Point and the surface geology of the shore to the 

 north, from St. John's Point to Killough. The Bay of Dundrum has for 

 the most part a flat sandy shore, backed by extensive sand-dunes, which 

 extend for a distance of six miles around the shore, and at low water 

 great stretches of flat sandy surface are exposed, whereas from St. John's 

 Point to Killough the shore is composed of the serrated edges of tilted 

 rocks in the wildest confusion, and of the grandest aspect. Here are 

 thin layers of fine shale laid down in deep still water; here are the 

 rougher grits of ancient shore-lines, and their upturned edges are now 

 cut through in all directions by varied forms of once molten volcanic 

 matter, that now stand out as dykes throughout the district. A rich 

 variety of rock specimens was secured here, and the marine workers 

 made good use of the favourable opportunity afforded them in the rents, 

 fissures, and rock-pools that abound along this sea-beaten coast. Four 

 species of Isopods were seen, the specimens of Li£2a occanica being 

 exceptionally large. 



Of land and fresh-water shells, some thirty species were collected, 

 the best of these along the drains and flax-pools in the White Bog — 

 an alluvial flat — where some of the sub-fossil shells were also found. 

 Of recent species, Hyalinia iiitida^ Aiiialia gagates ; a thin var. of Helix 

 nemoralis, fairly common in one hedgerow ; Vertigo antivcrtigo, V. pyguuca, 

 Aplexa hypnoruDi and Planorbis spirorbis, are worthy of record, the latter 

 being mainly the var. ecarinata. 



Coming near to Killough, the raised beach and the upper accumu- 

 lation of coarse gravel, which Harris, writing 150 years ago, called 

 " unripe sandstone," was noticed. This deposit, cemented by calcareous 

 matter, occurs along the shore from Killough by Ardglass, to some 

 distance northward. 



Killough, presenting such a variety of ph3'sical conditions, is known 

 as an interesting one for the botanist, yielding a number of plants 

 of rarit}'. On the coast the following were collected ; — Scutellaria 

 galericulata^ Sagina nodosa, Scnebiera didynia, and white Centaury. On 

 the roadside near the well, the Dwarf Elder, or Dane's-blood. was found ; 

 also one of the rarest local rushes, funciis obtusijlonis. Beta iiiaritivia 

 occurs near Killough station. Cichoritiin Intybtis was found in a grazing 

 field near the town. The principal discovery of the day was the Sam- 

 phire, Crilhiiium viaritiiinini. The sample was collected near St. John's 

 Point, where it is hoped it will be preserved, and not exterminated. 



September 10. — Excursion to Hoi<i.ymount, near Downpatrick. — 

 A bright day brought together a goodly number of members. Arriving 

 in Downpatrick, the party was joined by other members, and the 

 greater portion started in waggonettes for Hollymount grounds, while 

 another section of archteological taste set off in the opposite direction. 

 A drive of two miles brought the party to the entrance of the demesne, 

 and a narrow lane led to the marshes, which fringe the estate. There 



