138 
Nematoclirus filicollis Rud. 
The maximum diameter of the body varies between 90 and 130p. 
The lateral lobes of the bursa are without distinct dorsal lobules such 
as occur in N. spathiger. The postero-lateral ray is the thickest; the 
externo-dorsal is extremely slender. It was noticed that the posterior 
branch of the dorsal ray is frequently bifurcated at the tip, a point not 
previously recorded. The long slender spicules have an average length 
of 810p, varying between 750 and 925p. The terminal membrane of 
the spicules is lanceolate, ending in a fine point. 
Female. The average length of the adult female is 18 mm., the 
specimens observed varying from 13 mm. to 21 mm. The maximum 
breadth of the body just anterior to the vulva measures 150-225p. 
The tail is truncated posteriorly and from the tip projects a very slender 
rod-shaped process 12-18/z in length. The truncate tip of the tail has 
a breadth of 20-25p and the cuticle surrounding it is slightly inflated 
and frequently presents faint transverse striations similar to those in 
the neck region. The anus is situated 65-80p from the posterior 
extremity, the body at this level having a breadth of 45-60p. The vulva 
is a little less than a third of the length of the body from the posterior 
end. The vaginq is very short, the muscular portions of the two 
ovijectors measure 400-500p. The average size of the egg is 160p x 80. 
The Egg. 
The eggs of Nematodirus filicollis are considerably larger than those 
of most Nematodes which inhabit the alimentary tract of Ruminants 
in this country. I have measured a large number both from the sexual 
organs of adult females and from washings of faeces; as mentioned in 
the specific diagnosis it was found that they have an average length 
of 160p by an average breadth of 80p. The smallest egg observed had 
a length of 130p, the largest 210p, the breadth varying similarly 
between 65 and 95p. It is worth noting that the eggs from the faeces 
were always found to be a little larger than those taken from the maternal 
uteri. 
The shape of the eggs is fairly constant, appearing elliptical in side 
view, circular in cross section. The egg-shell is thick but quite trans¬ 
parent and colourless; the thickness, approximately 3p, is uniform 
and not increased at the two poles as in N. spathiger (according to 
Railliet and Henry). The surface of the shell is quite smooth. The 
eggs commence their development within the uterus and when laid 
usually contain seven or eight cells; more advanced eggs were never 
