OLDHAAr : ADDITIONS TO SOUTH DEVON .MOLLUSCA. 109 



Planorbis spirorbis. — In a ditch near Countess Weir. 



Valvata piscinalis. — Common in the canal at Topsham. 



Hydrobia jenkinsi. — In a ditch near Topsham. (Mr. Adams 

 will give particulars of this find in another article). 



Unio pictorum. — Two dead shells in the Exe at Topsham 

 Ferry. 



Pisidium amnicum var. flavescens. — All the shells which 

 we took in the canal near Exeter belong to this form. 



P. fontinale var. pulchella.— Common in ditches in Ex- 

 minster marshes. The \.y\i\c^\fon finale was taken in ditches 

 by the side of the canal between Exeter and Topsham. 



P. pusillum. — Common in Exminster marshes. 



P. milium. — -A few in Exminster marshes and the canal near 

 Exeter. 



Dreissensia polymorpha.— Small, in canal near Topsham. 



During our visit we had the pleasure of inspecting collec- 

 tions of local shells, made by Mrs. Smith and Mr. McMurdo. 

 They contain some beautiful series of the varieties oi JI. horf en- 

 sis and H. 7iemoralis, including very fine examples of Jwrtensis 

 var. rozeozonata. Mrs. Smith has a ventricose form of Anodonta 

 cygnea from the canal at Topsham, and Mr. McMurdo an ex- 

 ample of H. aspersa var. exalhida from a hedge-bank between 

 Topsham and Exeter. It may be mentioned that Hyaliiiia 

 draparnaldi occurs in Mr. McMurdo's garden. 



On a patch of grass by the road-side near Topsham, we 

 noticed three cases of union between typical H. virgata and the 

 var. lidescens, but did not observe any other couples. At Bud- 

 leigh Salterton, Mr. Adams subsequently noted a union between 

 the vars. lidescens and albicans. 



Mr. W. Denison Roebuck has kindly identified all the slugs 

 mentioned in the foregoing list, with the exception of A. hor- 

 tensis and A. agrestis, which we did not trouble to send him. 



October igt/i^ i8g2. 



