314 MILNE AND OLDHAM : MOLLUSCA OF BOWDON DISTRICT. 



Norbury Booths, and L3'mm. Moreover, almost every field 

 has its pit, from which marl was obtained for enriching the land 

 before the days of scientific farming. On the mosses, all now 

 drained, of Carrington, Hale, Baguley, Warburton, Tabley, and 

 Knutsford there are many ditches and pools. The streams of 

 the district all terminate in the Mersey, which is joined first by 

 a brook known successively as Baguley, Sinderland, and Wych 

 Brook, and fed by Fairywell, Timperley, and Caldwell Brooks ; 

 then by the BoUin, united with the Birkin, which brings the 

 waters of Ashley and Rostherne Brooks, and with Agden Brook. 



A considerable area is taken out of the district for collecting 

 purposes by the growing suburbs of Manchester, Altrincham 

 and Bowdon, and Sale and Ashton, in which the gardens may 

 serve to introduce some new species, but are mostly closed 

 ground to the naturalist. The large parks of Tatton, Mere, 

 Dunham, High Legh, and Wythenshawe also, being preserved, 

 are difficult to work. 



For the most part the distribution of moUusca will be found 

 sufficiently indicated in the following pages, but two localities 

 are so particularly fertile that they deserve special mention. 



Hampson's Pit is a pond of no great size at Baguley, 

 formed of an old marl pit, with a muddy bottom, overhung by 

 trees on one side, full of different species of water-plants, 

 especially Anacharis alsinastruni, and fringed on two sides by 

 rushes. In it have been taken Planorbis albus, vortex, umhili- 

 catus, corneus ; Limncca peregra and v. ovata, auricularia, 

 stagnalis, glabra ; Viviparus contecius ; Bythinia tejitaculata ; 

 Anodonta cygtiea, v. zeUensis and incrassafa ; Sphcerium corneum, 

 lacustre v. brochoitiatia ; Pisidiuin fontinale and v. heiislowana, 

 piisilluni, milium. L. glabra is represented only by one speci- 

 men, which had probably wandered in from a neighbouring 

 ditch ; and L. stagnalis and V. contedus are introductions. 

 Still, the list is a notable one, and its interest is increased by 

 the exceptional size to which most of the shells — especially P. 

 corneus, L. stagnalis, V. contectus, A. cygnea, S. lacustre, and the 



J.C., vol. vii., Jan. iSg-j. 



