190 Guide to Belfast. 



Mollusca, and it is here that so many of the rarer species of 

 Hyalinice and Helices abound. 



It was in these glens that William Thompson collected so 

 often for his lists of the Irish fauna. Colin Glen, near 

 Belfast, especially is repeatedly mentioned in his Natural 

 History of Ireland, and forty species may still be found 

 there. The late Prof. Ralph Tate, the founder of the 

 Belfast Naturalists' Field Club, collected frequently there 

 also. His finds in the Belfast district are often noted in his 

 work on British Mollusks. 



It is due largely to the number of these little rough 

 habitats that the district can claim as natives fully two-thirds 

 of the species of Land and Freshwater Mollusca that inhabit 

 Britain ; for the central area of Antrim is a high and in many 

 places bare tableland, with many peat bogs and few lakes 

 or old woods, while the greater part of Down is well culti- 

 vated, or in the southern portion covered largely with 

 granite mountains and bog, areas which have a poor mollus- 

 can fauna. Though the glens of Down, in Ordovician 

 rocks mainly, are fewer, and their land fauna hardly as rich 

 as those of Antrim, the former county has a more plentiful 

 and generally distributed freshwater fauna. This is mainly 

 due to the number of old cut-away bogs in the low ground — 

 areas from which the available peat has long since been 

 removed — with their multitudes of drains, marshes, ponds, 

 and flax-pools. Where latter are situated in marshy ground, 

 the heaps of stones that usually surround them shelter 

 during the winter sometimes large colonies of Vertigo anti- 

 vertigo and V. pygmcea, with Hyalinia nitida, H fiilva, and 

 H radiatula. The Lagan river and canal separating north 

 Down and south Antrim, and the Newry canal between 

 south Down and Armagh, also assist very materially the 

 Down fauna ; the former being the main habitat of 

 Anodonta cvgnea, a scarce species in the district, and the 

 latter of Amphipeplea glutinosa, which is both very local and 

 rare in Ireland. Some old woods in Down, though not 

 large in area, have a fauna hardly less rich in species than 

 the Antrim glens. Belvoir Park, near Belfast, is a good 

 example of these. In a few yards square at the Galwally 

 pond may be found Hyalinia radiatula var. viridiscenti-alba, 



