176 YORKSHIRE NATURALISTS’ UNION AT MALHAM, 
Helix pulchella. Malham. 
Pupa umbilicata. Close to Malham Tarn House, and also at 
Malham and the valleys above Malham Cove. 
Clausilia rugosa. Very common at Bell Busk. 
Clausilia dubia var. suttoni. Limestone rocks on Malham 
Plateau. 
Zua lubrica. Bell Busk. 
Sphzrium corneum, Dead specimens in the Tarn, common. 
Pisidium pusillum. Common in Malham Tarn. 
Bythinia tentaculata. Only dead specimens taken in the ‘Tarn. 
Valvata piscinalis. A very prolific species in the Tarn. 
Planorbis nautileus. Several specimens were taken in the Tarn. 
Planorbis albus. Malham Tarn. 
lanorbis contortus. Malham Tarn. 
' Physa fontinalis. One specimen in the Tarn (W.D.R.). 
Limnza peregra. The majority found in the Tarn were dead 
specimens. 
Limnza stagnalis. Only dead specimens were found in the 
Tarn, but were to be picked up abundantly on the bottom, and 
were as large and fine as in many lowland stations, although 
Malham Tarn is on an exposed open plateau with an elevation 
of 1,250 feet. 
Ancylus fluviatilis. Malham Cove. 
On comparing the terrestrial species noticed at this excursion 
with the published list of mollusca for Malham, there appear to be 
two additions, viz., Z. nitidudus and H. pulchellia, while the distribution 
of H. sericea has been extended. 
As regards the aquatic species, two boats were placed at the 
disposal of the party on the Tarn, but although four scoops were 
set to work, the results did not appear very encouraging. On 
previous occasions Potamogeton lucens had produced numerous 
Limnea stagnalis, but this time the collectors met with no such good 
luck. Only odd live specimens of Spherium, Limnea peregra, and 
Physa fontinalis were secured, whilst Valvata piscinalis was very 
plentiful. The other species obtained consisted altogether of dead 
specimens scooped from a sandy bottom, largely made up of the 
fragments of shells and other débris. It is satisfactory, however, 
to note that Physa fontinalis and Planorbis albus which appear on 
the list had not been previously recorded. 
For the Entomological section, Mr. G. T. Porritt, F.L.S., of 
Huddersfield, reported that the only Lepidoptera which had been 
Naturalist, 
