66 THE FILARIDAE 



mm.; head rounded, neck long; alimentary canal not differ- 

 entiated into esophagus and intestine; anus opens on a 

 papilla 0.145 mm. in front of posterior tip; vulva 0.6 mm. 

 from anterior extremity; uterus double and when full of 

 eggs and embryos nearly fills body; adults found free in 

 connective tissue at the base of the mesentery around the 

 pancreas, behind the pericardium, and behind the abdominal 

 aorta and suprarenal capsules; microfilariae (Plate VI, 

 Fig. 4) in peripheral blood show no periodicity; life history 

 unknown; effect on host apparently nil; found in tropical 

 Africa and British Guiana. 



5. Dirofilaria magalhaesi. Worms white, opalescent, 

 transversely striated; head club-shaped and simple; eso- 

 phagus with a bulb; tail rounded. Male, length 83 mm. 

 width 0.28 mm. to 0.4 mm.; cloaca D.ll mm. from posterior 

 tip; two unequal spicules; four pre-anal and three post-anal 

 pairs of papillae. Female, length 155 mm.; width 0.6 mm., 

 to 0.8 mm.; vulva 2.56 mm. behind anterior tip; anus 0.13 

 mm. in front of tip of tail.; lives in heart; life history and 

 pathogenicity unknown; found in Brazil. 



6. Onchocerca volvulus. Body white filiform, slightly 

 attenuated at the ends; cuticula transversely striated; head 

 rounded; mouth unarmed; alimentary canal straight and 

 un differentiated. Male, length 30 mm. to 35 mm.; width 

 0.14 mm.; tail strongly recurved and somewhat flattened on 

 its concave aspect; three pairs of papillae present on each 

 side of the anus; three pairs of post-anal papillae; two 

 unequal spicules the larger measuring 0.077 mm. and the 

 smaller 0.082 mm. in length; female, length 60 mm. to 70 

 mm.; width 0.36 mm.; cuticular striations ring like and well 

 marked; tail recurved; vulva 0.76 mm. from the anterior 

 end; found in sub-cutaneous tumors from the size of a pea 

 to that of a pigeons egg; usually found in axilla, popliteal 

 space, about the elbow, in the sub-occipital region and in 



