Teeth two or more 



KEY AND CHARACTERS 223 



New Genera 



The teeth more or less equal in size, and usually mobile 

 Oesophagus with median or posterior bulb or swelling, or both 



Onchi or teeth have an outward throw; amphids circular; spinneret present- -f Aponchivm 79 

 Onchi or teeth have an inward throw 



Amphids none, or so obscure as easily to escape notice; f-; teeth (?) 12 (Synodontium) 65 



Amphids present 



The amphids horse-shoe shaped, faint; striae fine, unaltered laterally; f- Synodontium 65 

 The amphids spiral, circular, or elliptical; striae fine, plain 



Shape of amphids spiral; winged; spinneret pres.; naked; head expanded. . (Pycnolaimus) 40 

 Shape of amphids round or elliptical 

 Terminus hamate; amphid minute, & the width of the head; winged Chambersiella 64 



Terminus not hamate; amphid J the width of the head; wingless; -f (Aponchium) 79 



Oesophagus plain, i.e. without median or posterior bulb or swelling 

 Onchi or teeth have an outward throw; amphids present; spinneret present 

 Form of amphids symmetrical to one line only; striae fine, plain; pharynx bulbous 



Ovaries two, 'f; onchi 3, duplex; cephalic setae 6 plus 6; head not set off Ironella 63 



Ovary single, f ' ; lip-region set off; lips 6, bipapillate; spinneret ventral Trissonchulus 78 



Form of the amphids spiral, circular, or elliptical 



The amphids spiral ; winged ; ' f ' (or -f-) ; lips bipapillate ; cephalic setae 4 Mesonchium 76 



The amphids elliptical; striae fine, resolvable, unaltered laterally; setae 4 Apodontium 62 



Onchi or teeth have an inward throw 



Amphids or unknown ; onchi small, apophysate, lips 12, appendiculate Gammanema 74 



Amphids present; spinneret present (questionable in Crystallonema) 

 Contour of the amphids circular 



Wings many; 3 mandibulate lips; setae in 3 circlets; cuticle rough Xyala 72 



Wing one or none; striae not altered on the lateral fields 



Cephalic setae none; armature of three biting plates or hooks; wingless Tripylium 71 



Cephalic setae ten 



Armature, 18 duplex radiating refractive ribs; winged; -f Monhystrium 69 



Armature, 6 talon-like or digitate labial elements; -f (Crystallonema) 67 



Contour of the amphids spiral; striae resolvable 



Winged ; ovaries reflexed or outstretched ; cephalic setae 4 ; pharynx cylindroid . Mesonchium 76 

 Wings absent; the 3 onchia enclosed in a bulb 



Onehj small, with heavy apophyses;, encl. in swelling; amphid of 2j-3J winds. Trogolaimus 75 

 Onchi large, without apophyses; phar. bulb spheroidal, amphid of li winds. .Synonchium 73 

 The teeth usually unequal in size, not mobile 



Oesophagus plain, i.e. without median or posterior bulb or swelling 



Amphids none, or obscure and escaping notice ; pharynx with many denticles ; ' f ' . (Thoo'nchus) 91 

 Amphids present 

 The amphids irregular, usually symmetrical to one line; spinneret present; 'f 



Form of the amphids not linear; striae fine, plain; pharynx denticulate ThoSnchus 91 



Form of the amphids linear; striae coarse, resolvable; cephalic setae 10 (Rhips) 118 



The amphids spiral, circular, or elliptical 



Form of the amphids spiral; striae coarse, plain, unaltered; spinneret present 

 Pharynx and onchi minute, obsc.; lips not thin; setae scattered ; amphids small. Croconema 112 

 Pharynx obv.; onchi plate-like, submedian; lips thin; setae 10; amphids large . Gonionchus 97 

 Form of amphids circular or elliptical; spinneret present (unknown in Gonionchus) 

 Winged; amphids large, faint; lips appendiculate; striae coarse, resolvable. .Anaxonchium 99 

 Wings none; cephalic setae 10; striae plain; lips thin 

 Ovaries 'f; striae fine; phar. with many denticles; amphids obscure, ellip.. . (ThoSnchus) 91 



Ovary -f ; striae coarse, contour cren. ; onchi plate-like; amphids spiral (Gonionchus) 97 



Oesophagus with median or posterior bulb or swelling, or both 



Amphids none or unknown; pharynx bulbous; striae fine, resolvable (Bolbolaimus) 100 



Amphids present 

 Form of the amphids linear; wingless; ovaries reflexed 



Spinneret present; 'f; striae coarse, resolvable; cephalic setae 10 Rhips 118 



Spinneret absent; 'f ; striae fine, plain; cephalic setae 6 plus 4 Myolaimus 60 



Form of the amphids spiral, circular, or elliptical 



Shape of the amphids circular; striae fine, unaltered laterally; spinneret present 

 Ovaries reflexed, 'f ; lips bipapil.; setae 4; submed. onchi minute; striae plain . (Polysigma) 106 

 Ovaries outstretched 

 Pharynx with distinct spherical bulb; striae resolvable; setae 6 + 6 + 4 . . Bolbolaimus 100 



Pharyngeal bulb a faint swelling; striae plain; cephalic setae 4 (Aponchium) 79 



Shape of the amphids a distinct spiral; cuticle wingless; spinneret present 



Onchus spear-like; lips minute, 12; cephalic setae 6 + 12 + 6; striae fine, plain. Mesodorus 105 

 Onchus very small, not spear-like; lips none or obscure 



Lips bipapillate, papillae conical; 'f; amphids labial; cephalic setae 4 Polysigma 106 



Lips non-papillate 



Setae in 6 longitudinal rows ; amphids opp. pharynx, \ the width of the head . A laimonema 107 

 Setae none; amphids not opposite the pharynx, J the width of the head. . . . Amphispira 103 



