A 
MONOGRAPH 
OF THE 
LAND AND FRESHWATER MOLLUSCA 
OF THE 
BRITISH ISLES. 
Poytum MOLLUSCA Cuvier. 
Crass GASTROPODA. Cuvier. 
SuB-CLass ANISOPLEURA Lankester. 
OrperR EUTHYNEURA Lankester. 
Sus-Orper STYLOMMATOPHORA A. Schmidt. 
FAMILY ZONITID/&. 
the liver. 
genitors of the L/mucide and other 
of Carpenter, reported from the 
referable to the # Piidonndas 
British Mollusca and their Shells,” 
HE family Zonitide (Swvirns, possessing 
a girdle) embraces the groups Zonites, 
Hyalinia, Huconulus, Gastrodonta, Zonk 
toides, Vitrina, and other genera, and is 
characterized by possessing a simple aper- 
ture to the semi-transparent spirally-coiled 
shell; the animal has the foot-margin 
defined by a pedal groove, which may 
form a caudal mucus-gland. ‘The marginal 
teeth are aculeate ; the Jaw is oxygnathous, 
and the ovotestis 1s usually imbedded in 
The primitive Zonitide are the pro- 
monata, and are amongst the most ancient 
known fossils. although the Zonites priscus 
measures of Nova Scotia, is more arene 
This group, the first of the truly tes- 
taceous species to be treated upon, i 
dedicated to the late Prof. Edward Forbes, 
joint-author with Sylvanus Hanley of the 
celebrated and classic work ‘‘ A History of 
as of numerous important and valuable essays on agin conchological, 
and botanical subjects. 
He was also the first to satisfactorily group the various diverse members 
of our flora and fauna on a comprehensive and scientific plan according to 
their geographical distribution and assumed origin, promulgating a theory 
explanatory of their presence in this country, which was forme rly almost 
universally accepted by scientists, and even at the present day has still 
naDy ardent adherents, 
12/6/06 
