TETRAPETALONEMA (T.) SAIMIRI SP. N. (NEMATODA: FILARIOIDEA) FROM COLOMBIAN SQUIRREL MONKEYS, SAIMIRI SCIUREUS

Tetrapetalonema (T.) saimiri sp. n., a filarial nematode from the subcutaneous tissues of squirrel monkeys (Saimiri sciureus) from central Colombia, is described. Within the subgenus, the small size of this worm (females 19-25 mm long) readily distinguishes it from several of the other species in which the minimum length exceeds 40 mm. Tetrapetalonema saimiri can be separated further from nearly all the other small species (T. dunni, T. barbascalensis, T. parvum, and T. obtusa) by its lack of annular body swellings, its low spicular ratio, the location of the vulva near the midportion of the esophagus, the shape and length of the tail in the female, and in details of spicular structure. Tetrapetalonema saimiri closely resembles T. panamensis, but is separated from T. panamensis by the salient buccal region, the acute flexure of the female tail, the shorter right spicule, and the configuration of the vagina of the former species. The microfilaria of T. saimiri is distinguished from that of all other known species of the subgenus by its consistent attitude (loose helical coil or closed C-shape) in 2% aqueous formalin preparations (Knott's technique). During an investigation of the filarial para- sites of Neotropical primates in Colombia, a distinctive microfilaria, easily recognized by its helical attitude in wet, 2% aqueous for- malin concentrates of blood (Knott's tech- nique), was observed in squirrel monkeys (Saimiri sciureus). Of 42 monkeys examined from Barbascal, Meta, 30 were infected with this microfilaria. Only one of 10 Saimiri sci-