PHARYNX 



(s. s. 441) 139 



Contour of the Maw. The contour of the pharynx differs somewhat 

 in the various species. If the dorsal onchus is strongly developed, the 

 profile indicates a roughly goblet-shaped or ellipsoidal cavity, and the 

 onchus extends well into the cavity so that its apex lies near the axis of 

 the head, sometimes up front and close to the inner margins of the lips. 

 If, on the other hand, the dorsal onchus is weak; and especially in species 



FlG - 8. Female of M. papillatus, a common cosmopoli- 

 tan soil-inhabiting beneficial species, known to feed upon 

 plant-infesting nematodes. The cesophageal glands (gl. 

 oe.) are well developed in this mononch; they empty into 

 the oesophagus and no doubt "lubricate" it during the act 

 of swallowing. This mononch is also syngonic. Sperm of 

 female origin is shown in the uterus at spm. For expla- 

 nation of lettering see page 129. 



M 

 mrit 



dec 

 ad dot 



where the wall is not much reinforced by longitudinal ribs, the contour of 

 the pharynx tends to be more or less oblong, so that its floor, lying in the 

 anterior end of the oesophagus, though irregular, is likely to be, on the 

 whole, more nearly flat. Opposite the dorsal onchus there is frequently 

 to be seen a faint transverse seam, most prominent along the ventral side 



