Reports to various Correspondents . 61 
Avion ater (Linn.), or the Black Slug, is found in damp woods, 
gardens, and hedges, and during the day under stones, logs of wood, 
and even tunnelling under ground. It reappears, however, directly 
after rain, and attacks all kinds of soft succulent leaves. It is a 
great pest in gardens and fields. At the same time it acts as a 
scavenger. This species has a variety of names on account of its 
variable colour. Ferussac named it A. empiricorum , on account of 
the calcareous matter found under the shield having been used in 
medicines. It is also now identified with A. Jlccvus, though at one 
time considered to be a distinct species. The shell of A. ater con- 
sists of small separate calcareous grains of unequal size. The colour 
of the body varies from black to red, yellow, green, brown, and 
occasionally a dirty yellowish -white, covered with large prominent 
tubercles, often much contracted and rounded in front and somewhat 
pointed behind. The mantle is paler than the rest of the body, the 
tentacles much swollen distally, foot with yellowish border, slime of 
a yellowish colour. The eggs, which are oval, white, opaque bodies, 
take about a month to develop. The young grow slowly, and 
apparently do not attain the adult condition until they are a 
year old. 
Limax agrestis, Linn., the Grey Field Slug, is by far the most 
injurious to vegetation of all the land Mollusca. It may be found 
in almost every garden and field throughout this country and most 
parts of Europe, as well as in Siberia, Madeira, and Algeria. It is 
the slug that has been so harmful in 1903. Like all slugs, its life is 
dependent on moisture. In dry weather we find it rolled up under 
a stone, coming out to feed by night and during wet weather. 
According to one authority, this mollusc feeds upon earthworms. 
In this case it has been probably mistaken for Testacella haliotidea , 
which preys almost exclusively on earthworms. The body is spindle- 
shaped, ashy grey, with reddish or yellowish tinge, and sometimes 
mottled. Early in the year it is of a much paler colour. The shield 
is large, the foot has pale sides, and it exudes an abundant viscous 
slime. The shell is oval and concave on under side, very thin, 
marked with indistinct lines of growth, with a broad membranous 
margin, obliquely striated. 
This species is most prolific ; as a rule seven or eight distinct 
batches are annually produced of fifty ova each. The breeding- 
season is from May to November. The ova are deposited in heaps of 
six to fifteen, in the ground and amongst moss. August, September, 
and October are the chief breeding months. A single snail will lay 
as many as 500 ova in the season. The eggs take three or four 
