19 



NOTES ON 



VABIETIES OF BYTHINIA TENTACULATA. 



GEORGE ROBERTS, 

 Lofthotise, Wakefield; Author of the History and Topography of Loftkowe, etc. 



Bythinia tentaculata monst. scalariforme. In July 1886, I found 

 one specimen of this monstrosity at Milford, near Pontefract. 

 The description is : — Shell conical, pointed at the apex j whorls 

 5 J, tumid, narrow; suture very deep; mouth round; length, 



11 mill. The shell very much resembles a coloured enlargement 

 of Bythmia leachii inserted in Tate's ' British Mollusca,' p. 34. 



Bythinia tentaculata var. major Locard. Specimens were found by 

 myself at Fairburn, in September 1886 ; and others have been 

 found near Bradford by Mr. J. A. Hargreaves. Locard's descrip- 

 tion of this, which I have obtained, along with others, through 

 the kindness of Mr. T. D. A. Cockerell, of Chiswick, is :— Shell 



12 mill, or more in length ; same form as type ; pale in colour, 

 sub-transparent' The Fairburn specimens were not pale but 

 reddish-brown in colour, 12 mill, to 14 mill, in length. 



Bythinia tentaculata var. nov. angulata. Specimens were col- 

 lected in 1886 by Mr. J. A. Hargreaves, in the canal near Brad- 

 ford. Description : Each whorl somewhat sharply angulated or 

 shouldered above the periphery, giving the shell a turreted 

 appearance; colour, reddish; length, 9-10 milk At p. 58 in 

 ' British Conchology,' vol i, Jeffreys mentions a single specimen 

 of Paludina vivipara (which is classed next preceding B. tenta- 

 culata) that had ' a keel occupying the place of the upper band.' 

 This would be a parallel form to the angulated variety of B, ten- 

 taculata. 



Bythinia tentaculata var. ?producta Menke. In September 1886, 

 Mr. J. Wilcock, of Wakefield, dredged a peculiar form (one 

 specimen) from a ditch at Fairburn. It is about 14 mill, in 

 length ; somewhat cylindrical ; suture deep ; spire pointed. 



Bythinia tentaculata var. zonata Baudon. Shell reddish, zoned 

 with one or more white lines or bands. Collected by Mr. 

 Hargreaves near Bradford. Noted also in my second volume of 

 ' Topography of Lofthouse ' (1885), p. 237. 



Bythinia tentaculata var. fulva Locard. Collected at Apperley, 

 near Bradford, November 1886, by Mr. J. A. Hargreaves. A 

 pretty variety of a shining tawny colour. Apparently new to 

 Britain ; I do not find it in any recent shell list. 



Bythinia tentaculata monst. decoUatum Jeff. I have specimens from 

 Kirkthorpe, near Wakefield, J. Wilcock ; near Bradford, J. A. 



Jan. 188"^. 



