276 WALKER: ON THE MOLLUSCA OF BIRSTWITH, YORKS. 



Zonites cellar! us. Very plentiful. 



Z. alliarius. Harrogate and other places, but not plentiful. 



Z. nitidulus. Very common. 



Z. nitidulus var. nitens. 



Z. purus. Found in several localities, but in small numbers. 



Z. purus var. margaritacea. Plentiful on a bank near Nidd 



Bridge. 

 Z. radiatulus. Common. 

 Z. crystal 11 n us. Very common. 



Z. fulvus. Found in a damp beech wood under decayed leaves. 

 Helix aculeata. Mossy bank near Birk Crag, Harrogate. 

 H. aspersa. Knaresbro', on limestone. 



H. n em oral is. Knaresbro', Pateley Bridge and many other 

 places; it seems to be more plentiful on limestone. 



H. nemoralis var. hortensis. Very common round Birstwith 

 on sandstone, but the species is very seldom found. 



H. arbustorum. Very abundant at Knaresbro'. I found a 

 broken shell on a stone heap at Birstwith, where it had 

 been dropped by a bird. 



H. rufescens. Very common. 



H. rufescens var. albida. Knaresbro.' 



H. concinna. Very common. 



H. hispida. Very common. 



H. caperata. Very common. 



H. ericetorum. Found near Birstwith, but rare. 



H. ericetorum var. instabilis. Found near Birstwith. 



H. rotundata. Very common. 



H. rupestris. Very abundant at Greenhow Hill near Pateley 

 Bridge. 



H. pygmsea. Nidd Bridge. 



H. pulchella. Nidd Bridge and Knaresbro'. 



H. lapicida. Eugene Aram's Cave, Knaresbro', and amongst 



J.C, iii., January, 1882 



