138 REPORT — 1839. 



monifera, although it has much in increasing the number of 

 the species indigenous to it. The difference between the cata- 

 logues of Mollusca pulmonifera of Cork, Dublin and Belfast, 

 is not great either as to number or otherwise. Helix glabella, 

 common about the two former, is not obtained near Belfast. 

 Helix pomatia, carthusiana and lajncida, and Limneus elon- 

 gatus, appear to have found their way into the Irish catalogues 

 by mistake. In Ireland the distinction between the Faunas 

 of the eastern and western coasts is not so marked, as respects 

 the Pulmoniferous Mollusca, as in England. 



District VIII. — The southern half of Scotland might be di- 

 vided into two great geological districts, the one favourable and 

 the other unfavourable to the development of its Fauna. The 

 unfavourable portion is the southernmost, and consists chiefly 

 of slaty rocks. The other division, extending to the edge of the 

 Grampians, is mainly composed of rocks of the coal formation, 

 and of trap, both favourable to the production of mollusca. 

 But climate here almost neutralizes the geological influence ; 

 the effect of which may, however, be still recognised in the 

 multiphcation of individuals on a genial soil. For the last 

 time in Britain we meet with Succinea oblonga, Helix fusca, 

 globularis, pura, aculeata, pygmcea and striata, Bulimus ob- 

 sciirus, Achatina acicula (these exceeding rare), Pupa anglica, 

 substriata, pygmcea, edentula and pusilla, Azeca tridens, all 

 the species of Planorbis and of Physa, and all the Limnei except 

 Limneus pereger and Limneus minutus, as also Ancylus 

 lacustris. The chief rarities of the south of Scotland are 

 Succinea oblonga and Pupa cylindrica ; the former found on 

 carboniferous sandstone, the latter on trap, and neither of 

 them as yet observed in the north of England. In the woods 

 of the district we find Helix scarburgensis and fiisca, Pupa 

 edentula, and occasionally Bulimus obscurus. The portions 

 most prolific in species are the neighbourhoods of Edinburgh, 

 Berwick, and Glasgow, partly, without doubt, in consequence 

 of the woods near those towns. There is but little difl^erence 

 between the Pulmonifera of the eastern and western divisions 

 of the district ; but among the fresh-water Pectinibranchia we 

 find Paludina impura on the western coast only. The south 

 of Scotland may be regarded as upland. 



District IX. — Climate sways the distribution in the ninth di- 

 strict. The hospitality of the Highlands does not extend to snails. 

 The bleak granite mountains, with their scant vegetation, hold 

 out but few temptations to the Pulmonifera. The species are 

 few, and the specimens are few. On the trap and under the 

 marine influence, in some of the Western Isles, they are some- 



