110 AGRIOLIMAX AGRESTIS. 
Protective Resemblance.—Tew observations have been made with 
respect to the protection this species may derive from simulating other 
animate or inanimate objects, but it has been suggested that there is a 
striking resemblance between this animal and the bloom-sheaths of the 
black poplar (Populus nigra), and also that the pale forms show a marked 
approximation in appearance to the cocoons of the Burnet moth (Zygana 
Jilipendula), this approximation being so close that at a short distance the 
resemblance seems complete; these, however, are probably only accidental 
vases of similarity, and can scarcely be compared with the remarkable 
examples of protective resemblance due to natural selection. 
Parasites and Enemies.—l'hough the enemies of this species are 
very numerous, its enormous fecundity enables it under ordinary conditions 
not only to maintain its ground, but to increase in numbers. 
M. Barthelmy affirms that a minute Nematode worm (A scurioides limacis) 
is found even within the egg ; while M. Laurent claimed to have detected a 
minute parasitic fungus therein, even before exclusion from the parent slug. 
The active Trichomonas limacis Duj., and the rotifer Albertia vermicu- 
laris are found within the intestinal canal of adults, and the hair-worm 
(Mermis nigrescens) in the body cavity, while at one time A. agrestis was 
regarded as the most probable medium through which the dreaded scourge 
Distomum hepaticum was conveyed to sheep and other ruminants. 
Ducks, rooks, pheasants, quail, etc., feed eagerly upon A. agrestis, a food 
to which the fieldfare also seems par ticularly partial. 
They are favourite morsels with the hedgehog, which often scratches them 
out from the crevices or from the roots of grass where they are concealed; 
while the Blindworm (Anguis fragilis) is said to prefer this slug to any 
other food, and in captivity will take four or five or even more at a meal. 
Fossil.—A griolimax agrestis has been recorded in the fossil state from 
many localities, and from many of the deposits belonging to the Post- 
‘Tertiary periods, but as the specific characters are not sharply defined on 
the vestigial shell, the identifications probably cannot in every case be 
implicitly relied on. 
Prrocene.—Mr. J. C. Mansel-Pleydell reports it as a Phocene fossil from 
Dorset, but it is not included by Kennard & Woodward amongst the 
Phocene fossils of the south of England. 
PLEISsTocENE.—Kennard & Woodward record it from Fisherton, in Wilt- 
shire, and also from Portland, Dorset, the specimens from the latter locality 
having been identified by Dr. Jeffreys. In Sussex, Mr. J. P. Johnson 
found it in deposits on the foreshore at West Wittering. In Kent, Ken- 
nard & Woodward chronicle its presence in the Ightham fissure, in the 
Happaway Cavern, at Swanscombe, Crayford, and Erith; while the Rev. 
R. Ashington Bullen records it from a pre-neolithic chalky-loam deposit 
on the Barton Court estate, Buckland, near Dover. In Essex, Mr. J. P. 
Johnson has found it in the Uphall brickyard, Ilford, and Mr. Miller 
Christy reports it as common in the Camm Valley alluvium at Cliignal; 
it has been reported from Copford, and also occurs in the Paleolithic river 
drift at Grays, from which place it was formerly recorded as Limaa sowerbyt. 
Kennard & Woodward state, on the authority of Dr. Jeffreys, that it has 
been found between Upton and Chilton, in Berkshire; and Mrs. McKenny 
Hughes reports it from the deposits at Barnwell Abbey, Cambridgeshire ; 
Sandberger (Vorwelt, p. 755) vouches for its occurrence in this country 
