MONOGRAPH OF BRITISH LAND AND FRESHWATER MOLLUSCA. 45 
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Hyalinia helvetica (Blum). 
1840 Zonites alliarius, var. 2, Gray’s Turton’s Man., p. 169. 
1870 — glaber Jetiveys, Ann. and Mag. Nat. Hist., p. 385. 
1849 Helix glabra Dupuy, Hist. Moll. France, p. 228, pl. x., f. 6. 
1881 Hyalina helvetica Blum, Nachr. Deutsch. Mal. Ges., p. 141. 
18s7 Euhyalina subglabra Clessin, Moll. Oesterr.-Ung., p. 72. 
1891 Vitrea (Polita) glabra Smith, Journ. of Conch., vi., p. 339. 
1903. — rogersi B. B. Woodward, J. of Conch., x., p. 809, pl. vii., ff. 2, 5, 11-18. 
1896 Hyalinia helvetica Adams, Manual, second edition, p. 47, pl. 2, f. 6. 
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ISTORY.—Hyulinia helvetica (Helvetia, 
Switzerland), is a species which was long 
confused with H. alliaria, H. glabra, aud 
other forms, and its specific status has 
only comparatively recently been satis- 
factorily established. 
Some time before 1870, the late Mr. 
Thomas Rogers of Manchester, a very 
acute and diligent botanist, as well as 
one of our most thoughtful and discern- 
ing conchologists, to whom the species 1s 
here dedicated, found examples at Marple 
in Cheshire, and was so impressed with 
their peculiarities that in 1870 he  for- 
warded specimens to Dr. Gwyn Jeffreys, 
at that time our foremost authority, who 
decided that they were referable to Zonites 
glaber of Studer, and this name was forth- 
with adopted for the species. 
CCD Although thus brought forward as new 
to Britain, the form had already been 
as noted by Mr. Alder and others, but was 
regarded by them as a large variety of Hyalinia alliaria, wider which 
ame specimens were sent out to continental couchologists by Reeve, 
Jeffreys, and others, and therefore gave rise abroad to much misappre- 
hension and confusion. 
Later investigations appeared to show that the modern reference to 
Zonites glaber was not really justified, and that such differences existed 
between the two forms as warranted specific recognition. 
Meanwhile Dr. Blum of Frankfort, who had collected similar specimens 
in Switzerland, was so convinced of their differential characters, that he 
described them as a new species under the name of Hyalina helvetica, and 
has recognized British shells as being perfectly identical with his species. 
IIerr Clessin, while accepting Blum’s species as_ valid, erroneously 
regarded it as identical with Bourguignat’s Zonites subglaber, which name 
as being the oldest he adopted. 
In 1903. Mr. B. B. Woodward, dissatisfied with all the previous names 
and allocations, again described the British specimens as new, under the 
name of Vitrew rogersi, partly led to Ins belief in its difference from 
Hyalinia helvetica by an accidental abnormality of the admedian teeth 
of the single continental specimen of H/. helvetica he had the opportunity 
of examining. 
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