KEY AND CHARACTERS 219 



PHARYNX PRESENT New Genera 



Wall of the pharynx unarmed (for alternative see page 221, midway) 

 Cavity of the pharynx conoid, or irregular 

 Oeosphagus with median or posterior swelling or both 

 Amphids none, or obscure; striae plain, not altered on the lateral fields 



Spinneret none ; head subtruncate, naked ; contour almost imperceptibly crenate . Cephalobellus 23 

 Spinneret present 



Striae coarse; pharynx minute (none?) without swelling; head non-striated. . . . (Leptonemella) 21 

 Striae fine; pharynx narrow, enclosed in a swelling; amphids minute labial tubes . (Catanema) 56 

 Amphids present 



The amphids linear; pharynx (?) ; striae coarse, plain; no wings; setae, 3 circlets . . Leptonemella 21 

 The amphids spiral, circular, or elliptical; when tubular, surface contour circular 

 Form of the amphids a distinct spiral; spinneret present 



Striae coarse; oesophagus =*= oxyuroid; wings 8; cephalic setae 6, subcephalic 4. . ..Dasynema 34 

 Striae fine, plain 



Lateral wings only on tail of male; ' f ; pharynx somewhat zigzag; setae minute. . (Zalonema) 7 

 Lateral wings absent 



Head with numerous scattered setae ; pharynx small, narrow ; onchi vestigial . (Alaimonema) 107 

 Head not with numerous setae; pharynx fairly well developed; teeth unobvious; 'f 



Cheeks thickly outinized ; cuticle thick Zalonema 57 



Cheeks, if thick, not heavily cutinized ; lips 2, large, lateral Pseudonchus 58 



Form of the amphids a circle or ellipse; striae unaltered laterally 

 Spinneret absent; striae fine 

 Intestinal cells with crystals; 6 lips, appendiculate; -f ; cephalic setae 10. ... (Crystallonema) 67 



Intestinal cells not with crystals; lips none; -f-; cephalic setae papilloid Anlicyathus 24 



Spinneret present 

 Head swollen, unstriated; no pharyngeal swelling; striae coarse, plain 



Cephalic setae 4; lips none; no labial papillae; amphids a single circle (Cinctonema) 22 



Cephalic setae none; lips 6, unipapillate; amphids two concentric circles. . . .Micromicron 104 

 Head not swollen or set off; pharyngeal swelling anon present; striae fine, plain 

 Pharynx narrow; amphids minute; male postanal organs tubular; setae 4 + 6. (Calanema) 56 

 Pharynx capacious; amphids well developed, opposite the pharynx or behind it 



Lips 2, lateral; pharyngeal ridges simulate teeth; 'f ; cephalic setae 4 (Pseudonchus) 58 



Lips 6, each with a digitate appendage; cephalic setae 10 (Crystallonema) 67 



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

 Amphids irregular 



Spinneret none; striae unaltered laterally; -f-; spiral amphid placed on a deltoid p&rt.Didelta 33 

 Spinneret present 



Striae altered laterally ; ' f ' ; head naked, set off; cuticle thick ; pharynx armed (?) .(Actinonema) 117 

 Striae not altered on the lateral fields 



Cephalic setae 12 + 6, in two circlets; -f ; amphid inconspicuous Leplogastrclla 28 



Cephalic setae 6, in one circlet; amphid 1 the width of the head; spinneret (?) . .Rhabdocoma 32 

 Amphids spiral, circular, or elliptical 

 The amphids in the form of a spiral; striae not altered on the lateral fields 



Spinneret none (?) ; amphid J the width of the head; naked; wings two Neurella 25 



Spinneret present 



Buccal cavity with cutinous frame, and 3 apophyses with small apical teeth. . (Trogolaimus) 75 

 Buccal cavity without distinct framework and without teeth of any kind; striae fine 



Ovaries 'f; striae resolvable; amphid of 4 winds; cephalic setae 6 + 10 Nannolaimus 36 



Ovaries -f-; striae plain; amphids simulating a circle 



Mouth cavity large and obvious; cephalic setae unknown, in any case few Margonema 27 



Mouth cavity small; head rounded; cephalic setae large, 4 (special) plus 6. . . .Linhomoella 35 

 The amphids in the form of circles or ellipses 

 Striae altered on the lateral fields by wings: spinneret present 



Head set off by a groove, its appendages varied ; striae coarse ; wings numerous . . Xenolaimus 30 

 Head not strongly set off, though usually well developed 



Ovaries reflexed, f ; naked; striae fine, plain; pharynx small, obsolescent. . . . (Nemanema) 2 

 Ovaries outstretched; pharynx well developed, but not large; cephalic setae present 

 Striae fine, plain; cephalic setae 6, segmented; -f- (Cytolaimium) 31 



Cuticle rough from subdivided wings; setae many; lips 3, mandibulate (?).... (Xyala) 72 

 Cuticle normal; lips 6, papillate, appearing somewhat fimbriate; striae plain . Daptonema 66 

 Striae not altered on the lateral fields 



Spinneret absent; striae fine, plain; female organs outstretched, except Rhabdocoma 

 Ovaries two, -f- 



Cephalic setae 6, plainly segmented; lips three, papillate Cytolaimmm 3 



Cephalic setae 4, not segmented; lip-region punctate, amalgamated Didelta 33 



Ovary one, subcephalic setae 4 



Cephalic setae 6: f ' ; lips 3, flattish, not digitate Rhabdocoma 32 



Cephalic setae 10; -f ; lips 6, small, digitate 

 Cells of intestine with crystals; amphids not raised; excretory pore labial Crystallonema 67 



Cells of intestine without crystals; amphids raised; tail with spicate setae Zanema 68 



Spinneret present 



Pharynx obscure 



Lips in two sets, outer large, low; inner soft extensions of the oesophagus. .JygonemeUa W 

 Lips not in 2 sets, amalgamated; ceph. setae 4, 3-jointed; phar. prismoid cup.(Rhadinema) tf 

 Pharynx more or less obvious; striae plain 



Female organs reflexed, f; striae fine; head naked; pharynx small (Memanema) 



Female organs outstretched 



Mouth cavity small, inconspicuous; cephalic setae 4 (special) plus 6 . . . (Linhomoella) 35 



Mouth cavity moderate , in a swelling ; ceph . setae 6 , plainly segmented ; -f- . Cytolaimium 31 

 Ovary one, -f; striae coarse; setae 12; lips 6, striate 



Lips conoid, striated, large, tipped with setae, and with a seta near base. Dactylaimus / 



Lips flat, papillate, appearing fimbriate, three-ribbed (Daptonema) 66 



Cavity of the pharynx more or less prismoid or cylindroid (not conoid or very irregular) 



