SHACKLETON : DISAPPEARANCE OF YORKSHIRE PLANTS. 79 
Bythinia tentaculata |. Found with Pa/udina contecta in both 
the above counties and at similar depths 
Bythinia leachii Shepp. From six to eight inches on one or 
two occasions 
Valvata piscinalis Mill. A very inactive mollusc; although 
I must have dug up some hundreds, I have never found them 
deeper than six inches, and rarely that. 
Valvata cristata Mill. With the preceding species. 
Planorbis vortex L. Rimmer states that this species buries 
itself, but states no depth. 
Planorbis corneus L. This is the only species of this genus 
that I have found buried at all, which I have frequently done 
at depths of from eight to ten inches 
Physa hypnorum L. Mr. Wm. Jeffery (Journ. of Conch., p. 305, 
1882) states that this species buries itself when the ponds dry up. 
Limnza truncatula Miill. This is the only Limnza I have any 
actual measurements a I have often taken it in three or four 
inches of mud, and on one occasion a single live specimen 
eighteen inches below i surface of a dried-up pond. 
NOTE—ORNITHOLOGY. 
Flamborough Bird-Notes.—The poor birds are having a hard time of it 
this severe weather x, which has brome several rare visitants to our coast. I have 
ee brou “wate in a Black Guillemot (Uria grylle) which is very rare here. Robert 
, feler informs me he had observed several pairs of the Red-breasted 
igen Mee serrator), also Goosander see eee ee Swans 
( S came o Headland to-day flying sou a great many 
ocks of Snow Buntings (PZectrophanes nivalis) and Bramblings (Fringilia monte- 
Jringilla) axe frequent y seen on the Headland. Several flocks of the Common 
Guillemots (Lomvéa ‘troile) have arrived on the ‘Cont at ATTHEW BAILEY, 
Mamborough, Jan. 21st, 1891. 
ERRATUM. —I hope you will correct the mistake made in ‘ The Naturalist’ for 
January, p. 12. Shorelark not Stonelark.—M. B. 
DISAPPEARANCE OF YORKSHIRE PLANTS. 
ABRAHAM SHACKLETON, 
Braithwaite, Keighley. 
offer for publication in ‘The Naturalist,’ the records of a few 
interesting plants that are now entirely exterminated in the localities 
cence, * 
March 1891 
+ 
