14 LAWSON, ON LIMAX MAXIMUS. 
pharyngeal sac. The roughened membrane with which the 
pharynx and tongue (for so the papillary organ must be 
termed) are covered, when seen under the microscope, is a 
very pretty object. It is covered by a multitude of closely 
set spines of a calcareous nature, arranged in linear order, side 
by side, the lines being placed one behind the other; each 
spine consists of a central portion or body, which is elliptical, 
and an exquisitely slender curved hooklet springing from this 
latter; the poimts of the hooklets all project backwards, and 
the spines are placed one behind the other, and not alternately, 
with an exceedingly small, rounded process rising from the 
membrane between every pair. The functions of the head 
are two, those of prehension and mastication, deglutition 
being achieved through the contractions of the gullet. Now, 
the first, as I take it, is performed by the jaw and lips, which, 
grasping the leaf or other portion of vegetable matter, bring 
it within reach of the pharynx ; arrived here, it is acted on 
by the salivary fluid which has been thrown into the pha- 
ryngeal bag, then by a series of compound movements of the 
tongue it is submitted to a rasping process between the 
hooklets of this latter and those of the pharynx, and eventu- 
ally, having been reduced to a state of very fine division, it 
is tilted backwards by the tongue, and being now within the 
grasp of the cesophagus is gradually carried onward to the 
stomach. The head is principally composed of connective 
tissue, but about the oral orifice on the inferior border, a con- 
siderable band of nucleated, unstriped fibres may be observed ; 
a few fibres of a similar description are mingled with the 
layers of connective web, and the tongue [beneath the spinous 
coat] is almost entirely muscular. 
The salivary glands are two in number, extremely delicate 
in texture, and of a pale-white colour; they lie on either side 
of the cesophagus, in the respiratory region, being covered by 
the heart and pericardial gland, and resting in part upon the 
great supra-cesophageal ganglia ; they are bound to the gullet 
by numerous arterial branches common to both, and are 
flattened and leaf-like in appearance. Each gland has a 
length of ~ inch, from side to side measures about } inch, and 
pours its secretion into the mouth by a long and narrow duct, 
which passes anteriorly from the gland, beneath the great 
ganglia, to the orifice of the gullet immediately above the 
pharynx, and in which I, less fortunate than Miller, have 
not detected ciliated epithelium. In general structure these 
glands are loose, and are made up of a number of minute 
lobules, arranged in clusters upon the terminal ramifications 
of the ducts. Microscopically, each lobule is of an oval shape, 
