COOPEK ANB LOYDELL : MIDDLESEX MOLLTJSCA. 229 



82. Physa acuta, Drap. 

 Eecordecl from the Botanic Grardens, Regents Park (J.C, vi, p. 306). 



83. Aplecta hypnoeum (L.). 

 One specimen at Lower Halliford. Also recorded from Acton, 

 usually in ditches, scarce (Cockerell, Zoologist, xliii, p. 299). 



84. Palfdestrijsta Jenktnsi (E. A. Smith). 



This species has been but recently introduced into Middlesex. 

 Probably the earliest record is 1904, when it was found in a ditch 

 by the side of the Thames above Richmond, near Marble Hill. The 

 shells were evidently carried thither from the lower reaches of the 

 river, and by the overflow of the tide carried to their present habitat. 

 A pond near also contains this species, showing its adaptation to 

 purely fresh- water conditions. 



In 1907 it was found abundantly in a bit of marsh by the Frays- 

 water at Uxbridge, and also in the stream itself. 



85. BiTHYNIA TENTACTJLATA (L.). 



Abundant in both stagnant and running water. 



Var. prodiida, Menke. Yiewsley. Beautifully banded specimens 

 are found in the Moat, Finchley. Decollated examples have been 

 taken fi-om a pond at Perivale. 



86. BiTHYNiA Leachii (Shepp.). 



Harefield, Uxbridge, Yiewsley, "West Drayton, near Colnbrook, 

 Lower Halliford, Shepperton, Chertsey, Hackney Marshes, and 

 Ponders End. It is also recorded for the River Brent (T. D. A. 

 Cockerell, S.G., 1884, p. 138); Tottenham (A. S. Kennard). 



Yar. alhida, Rim. Near Colnbrook and Hackney Marshes. 



87. YlVIPAEA VIYIPAEA (L.). 



In all the rivers and in most of the canals. It was formerly plentiful 

 in one of the Hampstead ponds, while some extremely fine examples 

 have been procured from the Botanic Gardens, Regents Park (B. B. 

 Woodward's coll.). 



Yar. efasciata, Pickering. Grand Junction Canal near Sudbury, 

 River Lea at Tottenham. A dwarf stumpy form is not uncommon in 

 the Thames. 



88. YlVIPAEA CONTECIA (Millet). 



Staines Moor (fine examples in a pond), ditch at Uxbridge Marsh, 

 Bushey Park (moat in enclosed grounds), stream at Lower Halliford. 

 Also recorded for iSTew River, West Drayton (Cockerell, Zoologist, 

 xliii, p. 179). It is decidedly rare in the county. 



89. Yalyata piscinalis (Miill.). 



Frayswater at Uxbridge, canal at West Drayton and Yiewsley, 

 River Colne at Staines Moor, Queen's River at Bushey Park, Thames 

 at Hampton Wick, Lower Halliford, Brentford, Bedfont, and Ponders 

 End. It is also recorded for Hendon (C. C. Fryer, S.G., 1889, p. 259) ; 

 River Lea at Tottenham (Canon Horsley, S.G., n.s., vi, p. 181). 



