MALARIA EXPEDITION TO NIGERIA 
21 
per rectum. They are then taken up by Daphnia ; bore through the intestine and lie 
In the body cavity, reaching i "7-2 mm. in length. They show a typical mouth with 
six papillae and a ' vestibulum ' ; only the generative organs are lacking. They are 
then swallowed by ducks and bore into the wall of the stomach and oesophagus. 
Stossich does not include this worm in his list ot Filariae. 
Filaria picae mediae. Manson ■ 
The male and female were found coiled up in a small white tubercle in the 
pocket of the semi-lunar valve ; the worms were encysted, and a minute opening in 
the covering of the cyst may be present. 
The male is about 18-5 mm. long ; diameter at the neck about 0*06 mm. ; 
greatest diameter about o - i8 mm., of alimentary canal about o - o6 mm., and of 
spermatic tube 0*08 mm. The tail is strongly incurved. Two spicules. One or 
two minute caudal papillae. The tail is blunted and slightly lobed and tapers down 
from the body. The mouth is simple ; oesophagus straight about 0-5 mm. long, 
terminates in the alimentary canal by a gradual dilatation. Alimentary canal is 
straight, and filled with a dark granular material. The integument is covered with 
minute bosses or tubercles, largest about the middle of the animal, less marked towards 
the head and tail ends. 
The female averages about 37 mm. in length ; greatest diameter of un- 
impregnated specimen about o - 2 mm. ; impregnated about 0*3 mm. The anus is 
at about o - i2 mm. from the caudal extremity. The vagina is infundibuliform, and 
opens at 0*25 mm. from the mouth. Mouth, oesophagus and alimentary are similar 
to those of the male. Expressed embryos measure o - 1 2 mm. long by 0*004 mm - 
broad. They have no sheath ; tails are truncated. 
In the blood of this bird, Manson found embryos apparently of two kinds, 
one about o - i mm. long; the other about o - 22 mm. ; intermediate sizes were also 
present. The smaller were languid, the larger very active in the movements. A 
jerking pouting oral movement was seen in both. Tails sharp and pointed. 
Filaria corvi torquatis. Manson 
The adults occur in the right ventricle, pulmonary artery and its branches. 
The male is about 0-3 mm. long; greatest diameter about o - i6 mm. ; 
diameter of neck o - o6 mm. Length of oesophagus o - 6 mm. ; diameter 0^04 mm. 
The body is smooth and very transparent. Mouth simple ; spicules double. No 
papillae. Tail tapers to a blunt extremity. Anus close to end of tail. 
Female 18-20 mm. long ; diameter 0*27 mm. Vagina opens 0-25 mm. from 
mouth. 
The blood of the bird contained two dissimilar embryos ; the larger o - 2i to 
0-25 mm. long, and o - oo8 mm. broad ; the smaller 0-13 mm. long, 0-004 mm - broad. 
1. Manson, Journal of the Shicicrr Club, vol. xi, 1880, p. 1 ;o. 
