174 



SLUGS , 



SLUGS. 



Field or Milky Slug. Limax agrcstis, Liuu. 



Black Slugs. Ation atcr, Linn. ; and A. Iwrtensis, Ferussac. 



1, L. cKjrcstis ; 2, L. ater (less than life size); 3, L. ater (var. empiricorum) 

 in repose ; 4, eggs. 



Slugs are injurious to almost every kind of crop ; therefore, 

 as they can scarcely be rightly placed under any special crop- 

 heading, I give a note of them under their own name, and 

 this also because they are entirely different in their nature to 

 insects.* 



The true Slugs may be generally described (when extended 

 or in movement) as being long, more or less spindle-shaped, 

 cylindrical or tumid, head prominent, " tentacles" (commonly 

 known as horns) four in number, and two eyes placed on the 

 tips of the uppermost pair of horns (see figs. 1 and 2). 



When at rest or alarmed they draw themselves together 

 into a lump as shown at fig. 3. 



The Field or Milky Slug, L. agrestis, figured above, is a 

 somewhat spindle-shaped kind, about an inch and a third 



* They belong to the Division Mollusca, thus describecl, " Animal in pairs, 

 the body and its appendages soft, inarticulate (not jointed), enveloped in a 

 muscular skin, commonly called the mantle, which is extremely variable in form, 

 and has developed either within or upon it a calcareous i:)ortion, consisting of 

 one or several pieces commonly called a shell." — Trans, from De Blainville's 

 " Manuel de Malacologie et de Conchyliologie," given in Sowerby's ' Concholo- 

 gical Manual,' p. 3. The Shell Snail, "Pond Snails" or Liiimaa, a,n^ Pond 

 Mussels, are familiar examples of Molluscs with shells, the true Slugs or Lhnac'uUe 

 have a small morsel of a kind of shell-like formation sometimes shield-shaped 

 placed on the fore part of the back under the skin called the mantle. 



