pulchella, Cochlicopa lubrica, Carychium mininum, Clausilia bidentata, Vertigo 
antivertigo, V itrina pellucida , Euconulus fulvus, Succinea putris . Among the 
Fresh Waters pecies, Limnaea stagnalis, L. palustris, L. glabra, L. truncatula , 
Pl.albus. PI. vortex, PI. fontanus, PI. crista, Paludestrina Jenkinsi, Valvata 
piscinalis , Unio pictorum, U . tumidus, Anodonta cygnea, Vivipara viyipara, 
may be expected, and a special look-out should be kept in the River Derwent 
for ‘ Vivipara contecta ’ as it would be most interesting if this species should 
be rediscovered and found still in existence near the district ‘ Wressle ’ 
where Dr. Martin Lister originally found it, 1678-81. Collectors should 
always bear in mind that there is ever the possibility of some hitherto 
unrecorded species turning up to reward the diligent worker. 
The following species were obtained in the neighbourhood during August 
Bank Holiday week-end, 1921 : — In the River Derwent, Bithinya tentaculata, 
Neritina fluviatilis, Pisidium amnicum, Sphoerium corneum and Limnaea 
pereger. From a pond and the dykes in the Ings towards Thorganby were 
obtained Planorbis corneus, PI. spirorbis, PI. contortus, PI. umbilicatus, 
Valvata cristata, Sphaerium corneum, Limnaea pereger, Aplecta hypnorum, 
Physa fontinalis, Sphaerium lacustre, Pisidium subtruncatum , Pisidium 
obtusale, and Pisidium milium. The last named was at that time a new 
record for Yorkshire S.E. vice county area. 
On the road side Helix nemoralis is to be found in many interesting 
varietal forms. 
FLOWERING PLANTS. — Mr. T. Stainforth writes : — The botany of 
Skipwith and Riccall Commons has been fairly well investigated. The 
date of the excursion is too early for many of the more interesting and 
characteristic plants to be flowering. Apart from the common itself, good 
collecting ground is to be found on the banks of the Ouse between Barlby 
and Riccall, and in ponds near Barlby on the south-west of Riccall Common. 
The Line Pits at Skipwith are good. 
On the common and its borders the following plants may be found either 
flowering or in sufficiently recognisable condition : — Ranunculus sardous , 
Chelidonium majus, Corydalis claviculata, Fumaria Boraei, Nasturtium 
palustre, Polygala vulgaris, Erodium cicutarium, Rhamnus Frangula, 
Ornithopus perpusillus, Potentilla silvestris, procumbens , and palustris, 
Poterium Sanguisorba, Sanguisorba officinalis, Drosera rotundifolia and 
intermedia, V accinium Myrtillus, Erica Tetralix, and cinerea, Pyrola minor, 
Hottonia palustris, Samolus Valerandi, Menyanthes trifoliata, Pinguicula 
vulgaris, Mentha pulegium, Littorella uniflora, Scleranthus annuus, Rumex 
maritimus , Salix repens, var. argentea, Juncus squarrosus and effusus ; 
the four Lemnas ; Alisma ranunculoides , Eleocharis multicaulis, Stirpus 
caespitosus and fluitans, Eriophorum vaginatum and angustifolium ; the 
Carices, dioica, pulicaris, muricata, echinata, ovalis, panicea and flava ; Apera 
Spica-venti, Deschampsia flexuosa, Molinia varia, and Nardus stricta. 
In the neighbourhood of the Ouse Bank at Barlby and Riccall have 
occurred Aquilegia vulgaris, Thalictrum flavum, Saponaria officinalis, 
Geranium pratense, Pimpinella major, Allium scorodoprasum, vinealp, 
oleraceum and carinatum, Colchicum autumnale (now in fruit), Orchis ustulata 
and Morio, Lister a ovata. 
The Rubi recorded for the Skipwith area are plicatus, carpinifolius , 
rhamnifolius , pulcherrimus , macrophyllus , leucostachys, mucronatus , Koehleri, 
and dumetorum. 
Ferns, Horsetails, Etc. — The vascular cryptogams recorded include 
Lomaria spicant, Asplenium ruta-murarua (Skipwith Church), Athyrium 
Filix-foemina, Lastraea oreopteris and Filix-mas, Osmunda regalis, Ophio- 
glossum vulgatum, Botrychium lunaria, Equisetum palustre and limosum, 
Isoetes lacustris and Pilularia globulifera . (It would be interesting to re- 
discover the two last named). 
Algae (Characese). — Nitella translucens has been found in ponds at 
Barlby end of common. 
A Meat Tea will be served at Headquarters at 5-45 p.m., at a charge 
of 2/3 each. 
A General Meeting will be held at 6-30 p.m. for the election of new 
members and to receive reports from Section Leaders. 
(viii) 
