Norwich Castle Museum. 123 
a doubtful native; preserved examples are in the col- 
lection, and a small external shell will be noticed near 
the tail which serves to protect its vital organs. This 
species appears to be a connecting link between the 
Slugs and the Snails, with both of which it has 
affinities. It is found in gardens, and its natural food 
is earth worms. 
We have now arrived at the great family of 
HELIcIDA, a very extensive one, containing the true 
Snails, and for convenience, broken up into eleven 
genera. ‘The first genus is that of Swccinea, of the 
three species of which examp'es will be seen; the 
largest is S. putris, the Amber Snail, the large body of 
this species and the oval shape of the shell, seemingly 
too small for its body, shows its affinity to the Slugs. 
Vitrina pellucida is a pretty little species, from its 
colour known as the Green Glassy Snail. The genus 
Zonites contains a number of small shells, some of 
them, when disturbed, give out an odour like garlic. 
The genus Ax, which follows, is the typical one of 
the family, and contains many interesting species. 
The two first, “7. damellata and aculeata, are very 
small, this is atoned for by the next species, the 
giant AZ. gomatia, the Apple Snail, which tradition 
says, but apparently with no confirmatory evidence, 
was introduced into this country by the Romans. 
Here the esculent properties of this fine species are 
neglected ; but on some parts of the continent it is 
much prized as an article of diet. Of A. aspersa, the 
Common Snail, and 7. zemorals, the Garden Snail, 
many varieties are shown; both specics are very 
numerous. Other interesting species are 7. cantiana, 
rufescens, carthusiana, hispida, pygmea, and others. 
Three species of Budimus are small but pretty elongated 
shells, and Pupfa, so named from the resemblance of 
the various species to a chrysalis, is a genus of small 
