134 LAND AND FRESH-WATER MOLLUSCA OF THIRSK. 



I liavc to acknowledge the kindness of various friends, in communicating 

 notices of stations, whose names will be found throughout the list. 



Neritina fluviatilis, Lam. Adhering to Utrieularia vulgaris. In slow 

 streams at Newsham Carr. — Wm. Foggitt. 



Bithinia tentaculata, Oray. Common in ditches and stagnant ponds. 



Valvata piscinalis, Lam. Not unfrequent in ditches at Newsham Carr. 

 Amongst Fontinalis antipyretica, in the Codbeck, Thirsk. — J. J. Binns. 



Arion ater, Gray. Abundant. 



Arion hortensis, Fer. Moist hedge bank, Grizzlefield, and in the Holmes, 

 Thirsk. 



Limax maximus, Linn. In cellars, and under stones; moist bank, Feliskirk. 



Limax flavus, Linn. Occasionally found in cellars. 



Limax agrestis, Linn. Very abundant. 



Limax hrunneus, Drap ? I found a few specimens in a shady situation near 

 Thirsk, which I could refer to no other than this species. They differed 

 materially from L. agrestis, especially in their darker colour, and comparatively 

 longer necks. I have repeatedly searched the locality since, but have not 

 been successful in procuring even a single specimen again, and have there- 

 fore thought it best to attach to the name a note of interrogation. 



Lim,ax arhoreus, Bouch. Plentiful on the bark of an ash tree on the top of 

 the moor above Hawnby, at an elevation of about 900 feet ! — Jno. 0. Baker; 

 and in a similar situation, near Feliskirk ! — O. R. Baker. 



Vitrina pellucida, Flem. Not uncommon amongst moss, decayed leaves, &c. 



Helix aspersa, MUl. Very common. 



Helix hortensis, List. Very common. 



Helix Tiyhrida, Pior. Not unfrequent. 



Helix nemoralis, Linn. Exceedingly common. 



Helix arbustorum, Linn. Amongst nettles in several places. Under Boltby 

 Scar, at an elevation of 700 feet. 



Helix Lapicida, Linn. On rocks along the westex*n edge of the oolitic 

 moorlands, Boltby Scar, WhitsunclifFe, and Rolston Scar, occasionally 

 plentiful. 



Helix pulchella, MUl. Frequently amongst moss, and at the roots of grass, 

 &c. 



Helix Cantiana, Mont. By the roadside between Thirsk and Thorpfield, 

 near Newsham ; Rievaulx abbey, and other localities. 



Helix fulva, Mill. A few specimens at Rainton heights, at an elevation of 

 900 feet ! — R. W. K. Long. Moist hedge bank, Grizzlefield, near Thirsk. 



Helix acuUata, Mill. Hedge bank near Boltby ; and in company with H. 

 fulva, at Rainton heights ! — B. W. K. Long. 



Helix granulata, Aid. Amongst nettles at Rievaulx abbey, and moist hedge 

 bank, Grizzlefield. 



Helix higpida, MUl. Numerous. In addition to the normal form of the 



