JOURNAL OF CONCHOLOGY. I5I 



OBSERVATIONS ON THE MISPLACEMENT OF 



THE NAMES OF TYPE AND VARIETY 



IN HYALINIA PURA. 



JBy W. nelson and R. STANDEN. 



(Read before the Conchological Society, December 7 1892). 



The great preponderance of the whitish form of this species 

 over the brown, wherever we have collected, has long seemed to 

 us a remarkable circumstance, and careful comparison of notes 

 with many friends, whose experience has been the same as our 

 own, further confirmed the suspicion that something must be 

 wrong in the definition of type and variety as given in Jeffreys' 

 ' British Conchology.' 



Being together in the neighbourhood of Newcastle, in 

 August last, we paid a visit to the Museum there expressly to 

 have a look through Dr. Joshua Alder's collection, and were 

 pleased to find in it a tablet containing a plentiful series of the 

 white form (var. inargaritacea Jeff.) mounted and labelled, in 

 Alder's handwriting, as the type of H. pura ; and on the next 

 tablet three specimens of the brown form labelled 'H. pura var.' 

 This, in itself, appears to us sufficiently conclusive evidence that 

 what we and others have been taught to consider the variety 

 is really what Alder intended for type when he described the 

 species, and that var. inargaritacea Jeff, is a misnomer. We 

 will, however, quote descriptions from all the authors whose 

 works we have been able to consult, and it will be seen that the 

 majority of the evidence is corroborative. 



The species was first made known by Alder in 1830, and 

 though a well-marked species, at once became a source of error. 

 For Jeffreys, in 'A Supplement to the Synopsis of the Testace- 

 ous Pneumonobranchous Mollusca of Great Britain,' read before 

 the Linnean Society, June 21st, 1831, dismisses it very curtly 

 as Helix nitidula var. (=placing H. pura Alder as a synonym). 



