63 



Yellowish - white rectih'near nematode 

 with strongy dilated globulous cephalic ex- 

 tremity and sharply tapering caudal end. 

 Anterior part of body dorsally curved, both in 

 male and female, in some more so than in 

 others. Posterior part sometimes rectilinear, 

 generally turned towards the ventral surfa- 

 ce. Cuticle not very thick, transversally 

 striated; the striations 0,0036 mm. from one 

 another, crossed by two or three light lon- 

 gitudinal striations. Anterior extremity sphe- 

 roid, when looked at sideways, voluminous, 

 easily seen by the naked eye; adjacent part 

 of body slighter. At the level of the cepha- 

 lic extremity near the angle of the lips, the 

 cuticle presents a very characteristic series 

 of ornaments. Two small lateral papillae are 

 found a little below the oesophagus about 1,10 

 mm. from head. No lateral alae. Nerve collar 

 situated at junction of anterior quarter and 

 posterior three-quarters of oesophagus, 0,650 

 mm. from anterior extremity. 



No excretory pore visible. Mouth bi- 

 valved with two divisions resembling the 

 two shells of a mollusk. Free rim of the 

 valves, covered with a serrated sheat of chitin, 

 stretched from one labial commissure to the 

 other. Each lobe with three external papillae 

 one dorsal, one median and one ventral. Lips 

 joined at the commissure by a delicate lon- 

 gitudinally striated membrane. Diameter of 

 cephalic extremity: 0,483 mm. Width of lo- 

 bes: 0,232 mm. 



Initial part of oesophagus strongly di- 

 lated like an amphora, middle part slightly 

 sinuous, posterior rectilinear and club-sha- 

 ped. At the level of the dilatation which 

 forms a kind of sub-oral capsule, the walls of 

 the oesaphagus are very muscular and 

 there is a lumen with a thick layer of chi- 

 tin. At the bottom of the amphora-like di- 

 latation, about 0,280 mm. from the head, a 

 triangular chitinous prominence on each 

 side of internal wall of oesophagus which 

 I consider to be teeth. Beyond the sub-oral 

 capsule the middle part of the oesophagus 

 is somewhat sinuous and narrower. 



Nerve collar at level of this segment. 

 Posterior part of oesophagus rectilinear and 



club-shaped, opening directly into intestine 

 by means of a special valvular apparatus. 



Walls of oesophagus consist of three 

 layers, outer one thick and abundantly sup- 

 plied with transversal muscles, middle one 

 narrow, separated from the former by a lon- 

 gitudinal, very réfringent band of uniform 

 aspect, with two lighter longitudinal li- 

 nes; internal layer thinner, finely granula- 

 ted, thickly covered with chitin, which com- 

 pletely closes the cavity. Length of sub-oral 

 capsule: 0,318 mm.; width: (in middle) 

 0,232 mm. Oesophagus: Length: 590 mm.; 

 greatest width: 0,251 mm. Intestine fun- 

 nelshaped in initial part, covering pos- 

 terior part of oesophagus; generally rectili- 

 near and ending in a small rectum, 0,186 

 mm, in length, separated by a sphincter of 

 transversal muscular fibres. 



Male: Posterior extremity, slightly ven- 

 trally curved, suddenly tapering from ano- 

 genital ridge, funnel-shaped, ending in a 

 sharp pointed chitinous formation, 0,026 mm. 

 in length. Sucker small, ellipsoid, muscular, 

 without chitinous ring, length: 0,279 mm.; 

 rim of sucker 1,255 mm. from caudal extre- 

 mity. Caudal expansions quite insignificant. 

 Ten pairs of papillae, arranged in two lon- 

 gitudinal series, in the following manner : 



Three pre-anal, ventral; two large, one 

 above the sucker, another below, and a lesser 

 one between sucker and anus ijearer the 

 latter. 



Four ad-anal, of which three ventral 

 arranged in a series, the first less than the 

 two latter ones, and a small lateral one 

 between the second and third ventral. 



Three post-anal, small, equal, of which 

 two ventral near the caudal extremity, and 

 one lateral a little above the first ventral 

 one. 



Two small spicules equal in size, not 

 attaining the lower limit of sucker, slightly 

 chitinised, somewhat curved, with very 

 dilated proximal and sharp-pointed distal 

 extremity; length of spicules: 0.527 mm.; 

 width: proximal extremity 0,076 mm.; in 

 middle 0,022 mm. Qubernaculum, slightly 

 chitinised, gently curved, 0,133 mm. long. 



