LAWSON, ON LIMAX MAXIMUS. 13 
The Digestive System, with the appendages which appertain 
to it, forms the bulk of the slug’s viscera, and in treating of 
it we have to speak of the following parts :—head, salivary 
glands, gullet or pro-stomach, stomach, liver, and intestine. 
The head is the most anterior portion of the body, and when 
deprived of the tentacula and integument which cover it 
appears as a solid, glistening, white structure, of a more or 
less spherical form, viewed from above, in profile seeming 
oval, the large end behind, and having, projecting from its 
posterior inferior border, a small, whitish, semi-transparent 
papilla. On its two sides, above, are seen the superior ten- 
tacles, and beside and beneath, various branches from the 
cephalic or supra-cesophageal ganglia; moreover, the two 
most anterior ganglionic masses are strongly united to its 
external lateral surfaces, and their branches wind around it 
as before described. It is about + inch long in an antero- 
posterior direction, and measures + inch transversely. In- 
teriorly it is hollow, has in front an aperture—the mouth 
—and receives at the most superior border of its pos- 
terior surface the commencement of the gullet; its cavity 
resolves itself distinctly mto two—the upper or true 
mouth, and the lower or pharynx—which must be described 
separately. 
The mouth lies superiorly, and has its position indicated 
by the conception of a right line uniting oral orifice and 
gullet, and which is horizontal ; the outer opening is provided 
below with a fleshy lip (a modification of the general integu- 
ment), which is partially divided by vertical slips into squarish 
segments, and plays the part of an inferior jaw. Above, the 
lip is absent, its place being taken by a very distinct and 
perfect maxilla. This is a horny or chitinous structure, 
about + inch wide and + inch long, which is soldered to the 
palate; it is of a brownish colour, and of a somewhat tri- 
angular outline, the base in front notched, and bent down- 
wards at right angles to the rest, thus performing the 
office of teeth; the apex pointing to the cesophagus, and the 
whole non-dental surface constituting, as it were, a second 
palate ; behind, and close to its junction with the gullet, are 
seated the openings of the salivary glands. 
The pharynx or inferior cavity is a kind of pocket or diver- 
ticulum, which I can compare only to an inverted and bi- 
sected hollow cone, flat behind and angular in front; it is 
lined with a roughened membrane, and has, pointing from 
it downwards and backwards into the visceral cavity, the 
papillary process above alluded to, which organ can, by an 
eversion, be brought forwards so as to lie obliquely in the 
