YORKSHIRE NATURALISTS' UNION. 



REPORT 



OF THE 



CONCHOLOGICAL SECTION: 



18 7 7. . 



ANNOTATED LIST OF THE 



LAND AND FRESHWATER MOLLUSCA 

 KNOWN TO INHABIT YOEKSHIEE. 



By W. nelson and J. W, TAYLOR, Leeds, 

 President and Secretary of the ConeJiologlcal Section, 



In preparing the annual report on the Mollusca (Land and 

 Freshwater) inhabiting Yorkshire, it appears to us of primary im- 

 portance first to issue an annotated Hst of the species at present 

 known to occur in our county, as a basis for future research. 

 FeeUng as we do that generahzations as to the range or distribution 

 of species are unwarranted, and may in certain cases lead to 

 serious error, unless based upon an extensive and widespread 

 series of reliable observations, we have therefore carefully collected 

 all accessible records and added thereto the observations of our- 

 selves and others. We also purpose continuing the good work 

 begun by Dr. Gwyn Jeffreys of reducing to the S3'nonymy of widely 

 distributed European species many of the forms described as 

 distinct by American and other authors. "We shall, in addition, 

 draw attention to doubtful allocations, and in cases where there 

 are conflicting opinions, or the identity of species is first suggested 

 by ourselves, we intend to reproduce the descriptions, so that our 

 readers may be able to follow their own judgment as to their 

 identity or otherwise, though we point out all cases that seem to 

 us improbable or erroneous. 



For nomenclature and classification Jeffreys' ' British Concho- 

 logy ' is adopted as a basis, occasion being taken to incorporate 

 such information as we have acquired in the nine years which 

 have elapsed since Jeffreys published his supplement, mainly the 



Trans. Y.N.U., 1877. Series C 



