SLUGS. 89 
a little way beyond the margin of the shell (s).” 
— Woodward. 
Testacella appears to live five or six years. 
Trstacetta Mavezt (PI. VL., fig. 37), a kindred 
species, is a native of the South-west of Kurope, 
and is confined to the coast; it was imported to 
Bristol about the year 1830, where it is now 
very plentiful, and has since been found at 
Devizes. The slug is of a dark brown colour ; 
its shell, which is represented in Pl. VL., fig. 37, 
is larger and more cylindrical than that of T. 
haliotidea. 
FamInty ONCIDIADS. 
The above group is allied to the true slugs, 
and was founded to receive certain slug-like 
animals destitute of any shell, and completely 
covered by a leathery mantle. The species are 
almost all inhabitants of tropical.countries, many 
of them living on the sea-shores, others m 
marshes and woods. The family is represented 
by one British species— 
Oncipium crLticum (Pl. VI.; fig. 41)—The 
body is oblong, covered with short, thick, convex 
tubercles; it possesses only one pair of retractile 
horns, which bear the eyes. The dental formula 
1s pele Sy 
70 
This species frequents the sea-shore, and 
