Blackburn: Molliisca of Driffield and Neighbourhood. 367 



Planorbis fontanus we have taken at Hornsea, North Froding-ham, and 



Wansford. 

 Physa fontinalis abounds. 



Aplecta hypnorum we have taken in a stream near Hornsea Mere. It is 

 said to have been found at Driffield, but the record needs confirming. 



BiTHYNiA TENTACULATA and B. LEACHII are very abundant in the canal and 

 streams, Wansford and Foston. So also are 



Valvata piscinalis and V. cristata. V. piscinalis is unusually large and 

 plentiful. 



Neritima fluviatilis is common in the river at Rotsea. A few specimens 

 were found by Rev. F. H. Wood at the lock on the Wansford Road in 

 the dead weed on the bank. 



Anodonta cygn.^:a is found at Foston. One specimen taken was 14^ cm. 

 X 7 cm. and weighed a little over 8 oz. 



Spherium corneum is common and fairly distributed. 



Spherium lacustre we have taken at Rotsea and Tibthorpe. 



PiSIDIUM AMNICUM. Driffield. 



PisiDUM subtruncattm = FONTINALE. Driffield, Rotsea, Beeford and 



Skipsea, Tibthorpe Wold. 

 PiSIDIUM PULCHELLUM. Lowthorpe, Beeford and Skipsea, Hornsea. 

 PisiuiUM PUSILLUM. Driffield, Foston, Rotsea, Hornsea, Tibthorpe Wold. 

 PiSIDIUM PUSILLUM var. CINEREA. Rotsea and Foston. 



PiSIDIUM NITIDUM. Kellevthorpe, Beeford and Skipsea, Skerne, Tibthorpe 

 Wold. 



PiSIDIUM OBTUSALE. No records. 



PiSIDIUM GASSIESIANUM. Driffield, Hornsea, Lowthorpe, Skerne, Tibthorpe 

 Wold. 



Nearly every pond, stream, and drain in the district has 

 Pisidia in it, an^ the species are well distributed. The Tibthorpe 

 Wold record is from a wold or made pond on Mr. Piercy's farm 

 cleaned out about seven years ag"o. It is now full of Pisidia. 

 This pond is about 400 feet above the sea level. The above 

 list is by no means exhaustive, but is a list of finds localised and 

 named. 



On the lacustrine deposit at Skipsea I found a number of 

 well-preserved specimens. They are, of course, very brittle. 

 What struck me most about them was their almost identical 

 similarity to present-day shells. I secured specimens of 

 Bithy7iia teyitac^ilata and B. leachii, one repaired, one with an 

 operculum in situ, one with a brown stain, the remnants of 

 an epidermis. Amongst other thing's I found a tiny operculum 

 of an immature B. tentactilata, LimncBa pereger, a fragment of 

 what I deem to be Physa fontinalis, Valvata cristata and V. 

 piscinalis, SpJieriiim corneum with both shells attached, and, as 

 far as I could tell, Pisidium amnicnni and P. roseum. There 

 were broken pieces of either an Anodonta or a Uiiio, but the 

 shells were not complete enough to identify. 



1904 December i. 



