HAiciins : I'Kcni.iAu form ok hyoromia fusca. 287 



The only cause of this heavier calcification and redder colour that 

 I can think of is the limestone soil and the amount of dead beech 

 leaves about on which the mollusc appears to feed. The bank on 

 which this shell is found is a Hmestone one facing north and very 

 damp, but sheltered both above and from the opposite side of the 

 road by trees. It is some six feet high, sloping at an angle of 

 45 degrees. The limestone cropping out here and there makes pockets 

 which most of the year are filled with leaves. Above the bank is a 

 mixed hedge of laurel, beech, birch, oak, sycamore, hawthorn, with a 

 few furze bushes. The bank is covered with thick grass, the only other 

 plant of note being the wild thyme. In about 40 yards of this bank 

 I have also taken the following : — Limax arboriun ; Avion ater, var. 

 brutmea ; A. subfusais ; A, hortensis ; Polita iudda, one ; P. cellaria, 

 common; F. rogersi, common; P. nitidula, common; P. pura ; 

 Vitrea crystallitia : E. fiilvus, one ; P. rotiindata, common ; H. 

 hispida, very common ; var. fusca ; var. depilafa, very common; var. 

 alba, one ; m. scalariforne, two ; one example looks from one view as 

 if two hispida had been stuck one on the other ; H. striolata, common, 

 but small ; • also a whitish variety ; H. aspersa, two dead shells ; 

 H. nemoralis, this shell is common and always very intense in 

 colouring; type missing; var. rubella, 123(45), very common and 

 heavily banded ; as the spot is sheltered, damp and shady, this is 

 what one would expect; var. rubella, 00300 and 00000, not rare; 

 var. libellula, 00300 and 00000, not rare ; var. castanea, a dark 

 chestnut brown, common ; var. fascialba (exactly like the illustration 

 in Taylor's MonograpJi), one ; var. lateritia, one ; H. caperata, two 

 dead shells ; P. obscura, common and large ; CI. laininata, common ; 

 never below five feet from the bottom of bank when alive ; var. alba, 

 two or three examples ; CI. bidentata, common ; C. miiiimutn, 

 common, on dead leaves ; Poinatias elegans, not common ; mostly 

 var. ochroleuca. 



Pisidium lilljeborgii in Merionethshire and Denbighshire. — I am now 



able to add two counties to the known range of this Pisidium in Wales. In 

 September I collected it in two Merionethshire localities : Llyn Gwernan, a tarn at 

 550 feet on the north side of Cader Idris, where it was associated with Sphceriiim 

 corneuni, vzx. Jlavescens, P. nitidtim, milium and hibernicum ; and Llyn y Garn, a 

 mountain tarn at 1,450 feet in Cwm Prysor. In a gathering which comprised 

 amnician, subtrnncatiim, pulchellitm, henslowanufii, nitidum, miliutn and hiberni- 

 cum that I made in the Shropshire Union Canal at Llangollen, Denbighshire, on 

 Sept. 19th, iMr. A. W. Stelfox detected a single small but otherwise characteristic 

 specimen o^ lilljeborgii. Its occurrence in such a place is interesting, for lilljeborgii 

 has been regarded as living exclusively in mountain lakes and tarns. — C. Oldham. 

 {Read before the Society, December 7th, 1921). 



