2f>8 Appendix 



Helir horti'mis; not common, but occurs at Fen Dittmi, 

 Haslingfield, Fulbourn, Cherryhintmi and March. 



En<t olwura; fairly common in and about Cambridge. 



Caecilioides acicula; in holes in gravel, Cambridge Station, 

 the Observatory, and alive at Hauxton (see p. 121). 



Jamin'ui ry/tndracea; Bracondale (Cambridge), Babrahani, 

 Hauxton, Baitsbite, Duxford. 



Vertigo pygmaea ; Roman Road on the Gogmagog. 



Balea perversa; on willows along Bourne Brook and on 

 elms N.W. of March. 



Clausilia laminata; Madingley, Haslingfield, Cherryhinton, 

 Fen Ditton. 



C. bidentata; Bracondale and Ravensworth (Cambridge), 

 Trumpington, Chenyhinton, Toft, Whittlesford. 



Dreissensia polymorpha ; March, Roslyn Pit at Ely. 



Unio pictorum; fairly common in Ouse and Cam below 

 Cambridge. 



Pisidium henslowianum ; Hobson's Conduit, Coe Fen, 

 Hauxton, Whittlesford. 



Cardium edule (alive) and Macoma balthica (dead) in 

 brackish waters of the Nene at Tydd Gotes. 



