MALARIA EXPEDITION TO NIGERIA 41 
The length of the worms averaged 13-4 mm., breadth 0*26 mm. 
Cobp.'s formula : — - — — 3_ 3> 5 •> 99 — 
— , 1-87, 2-40, 2-13, 1-06 
The cuticle is thick, transparent, ridged, is thinner at the anterior end of the 
worm. The head end (plate XI, fig. 4) tapers somewhat to 0*25 mm. ; there is a 
slight indication of a neck 0-25 mm. across. Over the position of the buccal orifice, 
which is terminal and central, there is a slight flattening on the edge of which are 
four small tubercles. The oesophagus is very long, and marked off by a constriction 
from the intestinal tract, which is seen to course down the worm, curving from side 
to side to end at the anus a little in front of the extreme tip of the tail. The tail end 
(plate XI, fig. 5) tapers for a considerable distance, and is incurved. The extreme 
end is bluntly rounded. The anal orifice is wide, placed on a slightly raised 
papilla ; through the orifice in some specimens, the tip, in others about 50 jx length 
of a single sharply pointed spicule, projects. 
The worms are too opaque for further details to be made out. 
F 
