MALARIA EXPEDITION TO NIGERIA 39 
Four 'spots' can be observed — all of which are constant : - 
1. A narrow slit; distance 22*0 per cent, of the length of the worm 
from anterior end. 
2. A bright oval lateral bay ; distance 29-3. 
3. A long portion in the middle of the worm in which the cell nuclei 
are few in number and stain less distinctly than the rest of the 
worm. Its middle point is at a distance of 61 This is 
characteristic of the worm. 
4. A lateral bay, similar to and on the same side as the second ; 
distance 84*9. 
Species of Filariae, the embryos of which were found, rut no adults 
Filaria serpentiformis 
Definitive host : Cinnyris fuliginosa. 
F. falciformis also occurred in the blood of this bird. The embryos were 
found in small numbers in the blood ; but many were present in the lung juice, 
while only a very occasional one was seen in preparations of heart's blood. 
In fresh specimens (plate XIV, fig. 8) the embryos measured 436 /u ; breadth 
6 - 2 M- They were very active, quickly coiling and uncoiling : only slightly 
progressive. The head end had no papilla nor spine, only a clear conical tip. Body 
contents granular, no distinctive spots. The tail end tapered gradually for about 
one-sixth of the length of the worm to a very fine point. 
In stained specimens (plate XII, fig. 1) the length was 339 m- Head end, 
which is slightly tapered, is round, and for a distance of about 10 n from the tip 
shews no nuclear staining. A single narrow band-like or V-shaped spot only, at a 
distance 1 9*9 percent, of total length of the worm from the anterior end can be 
made out. At the junction of the posterior and middle thirds is an indefinite 
area in which the stained nuclei are looser. The tail end consists of a single 
column of cells gradually diminishing in size. 
This embryo resembles somewhat that of F. sbekktoni, but it is much longer 
both in stained and fresh specimens and the arrangement of the 'spots' serves to 
distinguish them. 
Filaria opobensis. Nov. Sp. 
Definitive hosts : Hyphantornis aurantus. 
Hyphantornis. Sp. incert. 
Stained specimens only obtained (plate XII, fig. 2). The length of the 
embryo varies considerably both in specimens of blood from different birds and in 
