C. H. Treadgold 
117 
The thin subcuticular layer has the appearance of a syncytium. Its nuclei 
may be seen from time to time in any situation, but are especially distinct in 
the anterior millimetre of each lateral band, where they form an irregular 
double row. 
The four longitudinal bands are formed by thickenings of this layer. The 
two lateral ones are always visible in the anterior millimetre, but apart from 
this are seldom very distinct; I never succeeded in tracing them the whole 
length of the body as Looss was able to do, moreover their breadth does not 
correspond with Looss’s figures (Table I). The median bands are sometimes 
visible in the anterior millimetre; they are much narrower than the lateral 
bands. 
The muscular system. The muscle cells are well developed and often show 
the appearance of a longitudinal striation. Those measured, varied from 
1 to 3 mm. in length, by 0-03 to 0-04 mm. in breadth. 
The nervous system. The anterior edge of the circumoesophageal nerve ring 
(Plate IX, fig. 1, N.R.) is situated about 0*15 mm. behind the anterior ex¬ 
tremity in the <?, and about 0-2 mm. behind it in the $. Its breadth is 0-03 to 
0*04 mm. in the <L 0-04 to 0*06 mm. in the $. Two rounded masses containing 
nerve cells—the lateral ganglia (Plate IX, fig. 1, L.G .)—are sometimes to be 
seen embedded in its substance. Three nerve bundles (Plate IX, fig. 1, N.B.), 
of which the anterior is the largest, arise posteriorly on either side; they cross 
the body cavity and disappear in the parietes. Looss (1904) describes the nerve 
ring as being 0*025 mm. broad. Neither he nor other observers mention the 
presence of nerve cells. 
The anterior papillae. The two larger ones are 8 to 10 /z in diameter, ■ 
lateral to latero-median in position, and situated from 20 to 30 g in front of 
the base of the cephalic cone; they have the appearance of being subcuticular, 
and never project above the surface; a strand of nerve fibres can sometimes 
be seen passing to each. 
The four submedian papillae were never distinguished with certainty. 
The digestive system. The mouth is a simple funnel-shaped depression in the 
cuticle. 
The oesophagus averages 0*9 mm. in length in the <$, 1-2 mm. in the ?: 
its anterior portion is somewhat bulbous, while the diameter at the level of 
the constriction between the oesophagus and the mid-gut is very constantly 
0*04 mm. in the <$, 0*06 mm. in the $. A tube of gland substance extends from 
the base of the cephalic cone to the end of the oesophagus—the so-called 
oesophageal gland (Plate IX, fig. 1, O.G.). Circumferentially it is attached to 
and lies between the muscle cells, the gland substance projecting into the 
body cavity. These projecting masses are better developed laterally than 
dorso-ventrally, and are especially prominent objects just behind the base of 
the cephalic cone. Two ducts open into the oesophagus at the posterior border 
of the nerve ring, but are seldom visible. 
Looss describes a large dorsal and smaller subventral glands. Other 
