b BRITISH MOLLTJSKS. 



coil, on the spiral plan of growth which is developed and matured 

 in the whorled shell of the succeeding Family. 



The Limacinea shun the light of day, rarely indulging their vora- 

 cious appetites except at night. They inhabit gardens and roadside 

 hedges in damp places, and congregate in cellars and outhouses, 

 and under planks and stones around old walls, pumps and wells. 

 These remarks apply chiefly to the genera Arion, Geomalax, and 

 Limax, which feed on vegetable matter, though not entirely abstain- 

 ing from flesh. Testacella burrows into the ground to the depth of 

 from two to three feet, and feeds, or rather gorges, upon worms. 

 The feebleness of the shell-producing function in the Limacinea is 

 largely compensated by the faculty of secreting mucus of a particu- 

 larly viscid kind, from all parts of the body. The slug will lower 

 itself to the ground from a tree or shrub — and even from a shelf, 

 when brought into the room — by the mere accumulation of mucus at 

 the extremity of the tail hardening into a gelatinous thread. The 

 animal functions are not suspended during hybernation, and at other 

 periods, as in the snail ; and the animal is at all times more tenacious of 

 life. The continued secretion of mucus is necessary to the slug's exist- 

 ence ; when this facidty ceases and the integuments dry, the animal 

 dies. 



The geographical distribution of the Limacinea is almost world- 

 wide ; they are by no means so confined to temperate climates as 

 has been supposed. More observations have been made on them in 

 Europe than in other countries, but they have been collected by M. 

 Quoy and others, at New Zealand, New Hebrides, Australia, South 

 Africa, and Ascension Island ; and Mr. Ciuning saw numbers at the 

 Philippine Islands, although he did not preserve specimens. In 

 South America the family is plentifully represented by a genus un- 

 known in Europe, Vaginulus ; and in North America a genus is 

 known abundantly under the name TebennepJiorus in every part of 

 the country between Lake Erie and the G-ulf of Mexico. Some of 

 our European Limacinea have been transported to the United States, 

 and become naturalized there to a distance of a hundred miles from 

 the coast. The home of Testacella is in the Canary Islands. Its 

 appearance in the south of Europe and the British Isles is partly 

 due to transportation with exotic plants. It has rarely been observed 

 except in gardens, and mostly about the hothouse or conservatory. 

 T. haliotidea has long established itself in Guernsey. Its pre- 

 sence in that island was detected sixty years ago by Mr. Lukis, 

 and I have received specimens from him, while this sheet is passing 



