54 



The Na^turalist. 



especially if undertaken by a more experienced collector, will add 

 various species and varieties to the list. Such a result is still more 

 likely if the streams and the woodlands (which I did not exhaustively 

 search) are well examined. I do not anticipate, however, that Semer- 

 dale will prove a very prolitlc district, certainly by no means so pro- 

 ductive as Mill Gill and Whitfield Gills (situated on the other side of 

 the Yore) are. Its climatological conditions are against it. It is of 

 a northerly aspect, with the encircling hill-ranges to the south, between 

 it and the light and heat of the sun, and thus likely to be more cold 

 and bleak than the valleys which are situated on the northern side of 

 Wensleydale, facing the south. 



Anodonta anatina, L. Very abundant in Lake Semerwater. 

 Limncea truncatula, MiilL Common along road sides near Stalling- 

 busk, and near the bridge at Bainbridge. 



Ancylus fluviatilis var. gibhosa, Bourg. Found near Stallingbusk in 

 1877, by Mr. H. Crowther. 



Avion ater^ L., the black slug. Abundant about Counterside, Carr 

 End, Marsett, Stallingbusk, &c. Ranges altitudinally as high as 

 1500 feet on Raydale Grainings. 



A. hortensis, Fer. Common on Bainbridge village-green, and near 

 Stallingbusk, Marsett, and Counterside. 



Limax agrestis, L., the field slug. This usually common pest was 

 abundant everywhere. 



Succinea putris, L. Common at the foot of the Lake ; also found near 

 High Blean, and a single dead specimen near the waterfall in Bar- 

 dale. 



Yitrina pellucida, Miill. Young specimens abundant under stones on 

 Bainbridge village-green ; a few also obtained near Stallingbusk 

 and Marsett. 



Zonites cellarius, Miill. One found at Carr End, near Marsett. 



Z. alliarius, Miill. Not uncommon near Bardale Force, Marsett, 

 Counterside, High Blean, and Stallingbusk. 



Z. nitidulus, Drap. A few specimens found about Marsett, near the 

 Knight's Close, and Bardale Falls, and in Bank Wood, Cragdale. 



Z. radiatulas, Aid. Three or four specimens found under stones by 

 the road sides near Stallingbusk. 



Z. crystallinus, Miill. One specimen found in company with the last- 

 named. 



