MONOGRAPH OF BRITISH LAND AND FRESHWATER MOLLUSCA, 15 
GENUS HYALINIA Charpentier. 
(Vitrea, E. A. Smith; Zonites, Forbes and Hanley; Helicella, Tate ; 
Hyalina of many authors), 
HH genus MHyalinia - 
(vaAuvos, transparent) 
was first published in 
1837 by Charpentier, the 
name being suggested by 
Agassiz. ‘lhe use of the 
name //yalinia has been 
objected to on the ground 
that it has already been 
used in the somewhat 
similar although not iden- 
tical terms of /Tyalina and 
Hyulinus to distinguish 
genera of Reptilia and 
Lepidoptera. Mr. E. A. 
Smith has, therefore, sug- 
gested that the term Vitrea 
proposed by Fitzinger as a 
sectional name for /Hya- 
linia crystallina should be 
extended in its scope to 
embrace the group and 
replace //yalinia. 1 have, 
however, preferred to use the term V7trea in the restricted sense intended 
by the original author. 
The genus, as now defined, embraces the thin and more or less trans- 
parent species of medium or small size, which have been by common 
consent removed from their former close association with the typical 
Zonites, a group of larger and duller shells now almost contined to South- 
eastern Europe, though formerly ranging further westward, as testified by 
their remains in the inter-glacial deposits of the Neckar Valley, as well as 
in those of the Seine. 
The Hyalinie are subdivided by various authors into many groups or 
sections, 1n accordance with anatomical or testaceous characters. In this 
country we possess representatives of Huhyalinia, Polita, Vitrea, Huconulus 
and Zonitoides. 
With the genus Hyalinia, Dr. W. Kobelt, of Sachsenhausen, in Nassau, 
is associated, in token of his long and invaluable labours in the cause of 
conchology, and in recognition of the estimation in which his many 
admirable works are held. 
Generic Characters.—Hxrernatty, the yaliniw are distinguished 
by the thin, glossy, translucent, and usually depressly-coiled shells of 
moderate or small size, with sculptured nepionie whorl, and obliquely 
erescentic simple aperture usually without any noticeable thickening or 
expansion of the margins, although in certain localities some of the 
species display a tendency during adolescence to the formation of a row of 
ill-defined denticles parallel with the basal margin, 
