249 



CONCHOLOQICAL CLASSIFICATION, VARIATION 

 AND NOMENCLATURE. 



J. W. TAYLOR, M.Sc. 



Identification. — In The Journal of Conchology (Vol. X., p. 

 365), Mr. B. B. Woodward has essayed to clear up several 

 doubtful conchological subjects and amongst others he has 

 attempted to clarify the conception of the species of British 

 Viviparce. He gives an unsatisfactory and entirely misleading 

 resume of Mr. Sylvanus Hanley's observations upon the 

 Linnean specimens of the genus (Ipsa Linnsei Conchylia, 1855, 

 pp. 376-7) inaccurately stating that Mr. Hanley. finding the 

 Linnean specimens to consist solely of Vivipara contecta, 

 thereupon assumed that species to be the Linnean Helix 

 vivipara, and that he had then very ingeniously attempted to 

 explain away Linne's descriptive term ' imperforata,' presum- 

 ably to make it fit the V. contecta which Mr. Woodward 

 erroneously affirms to be the only species of Vivipara in the 

 Linnean Collection. 



All this and more is quite incorrect, as Mr. Hanley gives a 

 very excellent account of the species to which little exception 

 can be taken. 



Some time ago, Mr. Roebuck and I were authorised by the 

 Council of the Linnean Society of London to overhaul the land 

 and fr»shwater shells contained in the Linnean collections in 

 their possession and we found the specimens of Vivipara to be 

 chiefly Vivipara vivipara (L.), and that two of them bore in 

 Linne's own handwriting the significant numerals ' 603,' the 

 serial number distinguishing this species {Helix vivipara) in 

 the loth edition of the Systema Natiirce, and therefore are 

 without doubt the true Linnean types. 



Classification. — Mr. Woodward [op. cit., p. 353), and 

 again in conjunction with Mr. Kennard (Post Pliocene Non- 

 Marine Mollusca of Ireland, 1918, p. 161) essays to improve 

 the classification of the Hyalinice, by uniting under the genus 

 Polita Held the various species which I have separated under 

 the headings of Euhyalinia and Polita (Monograph, Vol. III., pp. 

 18 and 67) ; but as I shall now endeavour to show, this suggested 

 grouping is such an incongruous medley of species as to render 

 their proposal not merely useless, but positively retrogressive 

 in its influence, for it should be borne in mind that the Zonitoid 

 shells are probably not monophyletic, but composed of diverse 

 groups, whose history and lineage have yet to be elucidated, 

 but which have arrived at a similar stage of shell degeneration, 

 and therefore exhibit a superficial similarity misleading to 

 those who have not closely studied the subject. 



The genus Polita is said to be especially typified by P. 

 nitidula, and represents a group markedly different in numerous 



1918 Aug. 1. 



