NELSON ANt) TAYLOR t ON YORKSHIRE MOLLUSCA. 75 



by Mr. J. Emmet — to whom Mr. Bean communicated the 

 information — to be what is now the ornamental water in the 

 Ramsdale Valley, Scarborough. 



The animal has been described as of great size and very 

 active, but these statements were not borne out by the Skidby 

 specimens, which were very indolent and inactive, and the foot 

 did not appear to be proportionately larger than that of the 

 ordinary Z. peregra. The extended portion of the mantle is 

 unicolorous grey and very mobile, and is constantly varying in 

 its amount of extension, 



Nyst and Maltzan state that this species appears chiefly in 

 March and April, which exactly agrees with our own observations. 



Mr. G. H. Parke, F.L.S., in Hobkirk's 'Huddersfield,' 

 hazarded the unfounded opinion that Z. glutinosa would eventu- 

 ally prove to be an aberrant form of Z. peregra. 



10. Coins — In Hobkirk's 'Huddersfield," p. 224, Mr. G. H. Parke, re- 

 cords the finding, in 1864, of three specimens of a shell closely 

 approaching in appearance L. glutinosa. 



22. Upper Dei went — Scarljorough (W. Bean, in Theakslon's 'Guide to 

 Scarborough,' ed. >;., ]). 1S7, 1871). 



24. Holdeiness — Abundant in Skidl^y drain, Hull. 1889 and 1S90! F. W. 

 Fierke, Journ. of Conch., vi., 251, July, 1890. 



Sub-Genus RADIX Montfurt. 



Shell subovate, last whorl ventricose; aperture more than half the 

 length of the shell, greatly expanded. — Binney and Bland, 'Land and 

 Freshwater SlicIIs of North America,' part ii, p. 30, 1865. 



Mantle not extending beyond the margin of the shell. 



Leach's name Gulnaria is i)erhaps more generally used 

 than the name given by Montfort, which, however, has the 

 priority. H. and A. Adams use Klein's name, Neritostoma, 

 but according to Mr. Binney, the figure and description given 

 by Klein refer rather to Succinea than to Limngea, in which 

 sense the name is used by Herr Clessin. 



