32 THOMPSON YATES LABORATORIES REPORT 
convexities of the worm is seen to be distinctly striated transversely. The outer 
lateral ridge bears a number of flattened transparent nodules, the distribution of which 
seems to be irregular, in places appearing to be grouped into twos, threes, or fours. 
The striations of the cuticle become spread out in the nodules. The striations are 
less distinct along the other lateral border of the worm. The anterior portion 
(plate V, fig. 2) tapers considerably ; its extremity is rounded ; the oral orifice is 
central and terminal — no papillae or other appendages could be made out. The anus 
is in a position similar to that nt F. spiralis (plate V, fig 3). The vagina opens at 
a distance of 0-45 mm. trom the anterior end. The opacity of the worms makes 
it difficult to observe further the internal anatomy. The nodulated cuticle is very 
characteristic. 
The male is much shorter and thinner than the female and has six coils. The 
tail end is markedly incurved. The length of the worm is 9*0 mm., breadth 
o - 1 2 5 mm. 
Lobb s formula 
- ™> °"93> i*4> °'4° 
The cuticle is ridged, knobbed, and striated, similarly to that of the female. 
Beneath the lateral ridges in the musculo-cutaneous structure is a dark brown granular 
pigmented layer : the pigment, apparently intracellular, is regularly interrupted by 
what appear to be large unpigmented nuclei. The head end (plate V, fig. 4) is 
similar to that of the female. The oesophageal bulb is very indistinctly marked. 
The anal aperture is at a distance of 0*058 mm. from the tip of the tail, and is at 
the centre of a low flat papilla. Three pre-anal, and two post-anal papillae could be 
made out on each side, the former being very small and close together, almost con- 
tinuous with one another. There are two unequal spicules, their terminal extremities 
have a rosette appearance. The origin of the reproductive tube can be seen to 
commence as a thin single tube coiled about the neighbourhood of the commence- 
ment of the intestine, which increases in size to fill almost completely the whole 
body cavity up to the last coil of the worm where the tube becomes thinner and its 
walls more muscular till it ends at the rosette horns of the spicules. The tail end 
differs from that of F. spiralis having no expansions of the lateral cuticular ridges, 
these disappearing altogether as the tail is reached. The tip is bluntly rounded 
off on the dorsal surface. (Plate V, fig. 5). 
The embryos are found in peripheral and central blood. In the fresh condition 
they measure 141*7 /m in length, 6.5 /x in breadth. They exhibit forward and backward 
sinuous progressive movements. They have a well marked thick cuticle which shews 
distinct transverse striations (plate XIII, fig. 4). They taper very slightly towards 
the anterior end, very abruptly posteriorly-, so that this end resembles in shape the 
point of a wire nail. The head end is bluntly rounded and has a small clear area- 
no prepuce nor spine could be made out. At the tail end the cuticle is well seen. 
