Filaria wäkerlini sp. n.

(Institute of Tropical Medicine and Laboratory of Comparative Pathology and Parasitology of Leyden.) Four females 2) were collected by J. C. Wäkerlin in 1909 under the skin of a Cercopithecus brazzae, which died in the zoological garden of Rotterdam. The monkey originated from the Mid-Congo in Africa. Three of these worms were available for study, the caudal part of the fourth of them being wanting. The examined worms (I, II and III) are 49, 59 and 60 mm. in length. The head-end, which has no papillae, in the 59 mm. long female is slightly swollen; near the end of the oesophagus it measures 720 µ in breadth, while the rest of the body is 510 µ broad, except the body-end, which tapers to the tail, where it is 260 µ broad in the vicinity of the anus. The cuticle is rather smooth, without transverse striations. A small mouth-opening, without lips, gives entrance to a 1 mm. long and 59 to 96 µ broad oesophagus, which is followed by a very narrow (less than 50 µ in diameter) intestine. The anus is situated at a distance of 350 p from the end of the tail, which downwards suddenly becomes thinner and ends obtusely. The vulva in the three named worms is situated anteriorly at a distance of 1.6, 2.3 and 1.7 mm. from the anterior end of the body. It is a long and narrow aperture leading into a small chamber, from which a very short, non muscular vagina originates. The trunk of the two uteri is not very long, extending only till some 100 µ beyond the end of the oesophagus. The two uteri run parallel to each other and extend backwards at a length of 22 mm. Then one of them bends backwards, runs