MALARIA EXPEDITION TO NIGERIA 37 
In the Hyphantornis a cyst occurred under the skin of the thigh and contained 
two worms. 
The cyst (plate X, figs. 1 and 2) is a thin-walled delicate fibrous tissue capsule 
which is whitish in colour, almost transparent and closely applied to the worms which 
it contains. The worms are often difficult to separate entirely from the enveloping 
capsule. The cysts seem to contain no or extremely little fluid ; each has always 
two worms, a male and a female. The colour of the contents varies from white to 
yellow, according to the colour of the contents ot the intestine canal of the worms. 
The dimensions of the capsule vary : the largest was 5*7 by 3-4 mm., the smallest 
p8 by 1*2 mm. 
The female worm, in one completely dissected-out specimen, measured 
40 - 6 mm., breadth 0-44 mm. 
- 0-98, i-86, 1-26, t 
Cobb s formula : 7 =-7 
— , 0-69, 0'86, 0.75 — 
The cuticle is thin and smooth. 
The head end (plate X, fig. 3) tapers somewhat, and is bluntly rounded. 
The mouth is terminal ; there are no papillae nor other appendages. The oesophagus 
is straight, has no bulb ; it is 0*54 mm. long, is light in colour, and indistinctly marked 
off from the darker intestinal tract. In the tract of many specimens are numerous 
bright orange-coloured round clumps of material — which give rise to the yellow 
colour of the worm. These clumps are irregularly shaped — some round and others 
angular. The tail end (plate X, fig. 4) is bluntly rounded ; the anal orifice is 
terminal. The vulva is situated on a small conical papilla, 0*25 mm. from the 
anterior end. The vagina extends directly, or after one or two forward twists, down 
the body of the worm for i*6 mm. distance from the orifice, where it receives the two 
uterine horns. These resemble those of the Ft/aria already described. There is a 
well marked 'pylorus' beyond which the tube is continued for 4*48 mm., to terminate 
in a blunt, slightly nodular end. The ova, containing coiled-up embryos, measure 
26 m by 19*5 ix. The embryos are 81 /x long. 
The male in shape and appearance resembles the female, but is much smaller. 
Length 4 - 5 mm.; breadth 0*17 mm. 
Cobb's formula : — > 3 64, 9 ^> — 5°' 97 6 
— , 2-64, 2-64, 3.80, 2-32 
The ends, both anterior (plate XI, figs. 1 and 2) and posterior (plate XI, figs. 1 and 2) 
are similar to those of the female. Width of head, o. 1 1 mm. ; of tail end, o - io mm. 
Length of oesophagus, 0*39 mm. The anus is ventrally placed, a little in front of the 
posterior end of the worm. There are probably two spicules : one, sharply 
pointed, is extruded in some specimens ; the other could be but very indistinctly 
made out. 
The embryos occur in both central and peripheral blood. They have no 
sheath. Length in the fresh blood 94-5 /x, breadth 3-5 m- The head end is slightly 
