466 PROCEEDINGS HELMINTHOLOGICAL SOCIETY VOL. 2, NO. 1 



Stroke of teeth inward; amphid occasionally obscure (for alternative see preceding page) 

 Spinneret 0; phasmids present; odontia 6; oesophagus cephaloboid; ovaries reflexed 

 Nema usually cephalated; cirri 0; amphid round; soil & fresh water; '?'... . (Teratocephalus de Man 1876) 



Nema not cephalated; cirri 6; amphid oval; tail hooked; in bark, etc.; '9 (Chambersiella Cobb 1920) 



( = Diastolaimus Rahm 1928) 

 Spinneret present 

 Mandibular jaws 2 or 3; pharyngeal and cardiac bulbs strong; marine 



Jaws 3; amphid not known; c? only Fusonema Kreis 1928 



Jaws 2, lateral, dentate; amphid multispire Cheironchus Cobb 1917 



( = DignathonemaFil. 1918) 

 Mandibular jaws absent 

 Amphid multispire; lips flat, confluent; pharynx rather narrow; marine 



Striae very fine; wings 0; labial papillae not seen; d" only (Alaimonema Cobb 1920) 



Striae icoarse, of dots; wings pres.; labial papillae 12; -?-, or reflexed at tip (Mesonchium Cobb 1920) 



( = Pepsonema Cobb 1920) 

 Amphid not multispire 



Habitat soil;amph.monospire to crook-shape ;phar. 6%;nema small,0.2 mm.;J (Pycnolaimus Cobb 1920) 

 Habitat marine; pharynx under 2%, not tubular; ovaries not reflexed 



Vulva 15%; odontia 12, minute; amphid "folded"; 9~ Synodontium Cobb 1920 



Vulva 81%; odontia 0; onchia 3; pharyngeal swelling slight; ~9 (Aponchium Cobb 1920) 



The teeth unequal in size, usually not mobile radially; amph. usually not obscure (from preceding page) 

 External amphid not spiral, circular nor elliptical; ovaries 2; spinneret present 



Gonads 9 outstretched ;amph. long, reaching sometimes to mid-body ;odontia6r?~PseiioW/a Cobb 1920 

 Gonads 9 reflexed; amphid a transverse slit 



Striae fine, plain; onchia dorsal and ventral Deltanema Kreis 1929 



(cf. Metalinhomoeus de Man 1907) 



Striae resolvable into elements; dorsal onchium usually the largest 

 Spicula of 2 joints; striae forming "basket-work" on neck; amphid opp. base pharynx Rhips Cobb 1920 



Spicula entire; striae of dots ; amphid near lips Chromadora Bast. 1865 



External amphid spiral, circular or elliptical 

 Female not known; spinneret present; marine 



Amphjd multispire ;head conoid;onch. minute;ceph. & subceph. setae in sets of 4 Alaimonema Cobb 1920 

 Amphid circular, elliptical or monospiral 



Pharynx surrounded at base by cuticularized ring Cricolaimus Southern 1914 



Pharynx not surrounded by cuticularized ring 



Striae of dots, interrupted laterally; pharynx cyatholaimoid, onchium large Endolaimus Fil. 1922 



Striae unaltered laterally; pharynx small; cf supplements tubular, post-anal Catanema Cobb 1920 



Female known 

 Ovary! 



Gonad 9 outstretched ;spinneret pres. ;cf supplements numerous,complex;marine Aponchium Cobb 1920 

 Gonad 9 reflexed; amphid small, circular, obscure; spinneret 0; not marine 



Cardiac bulb valvate, median bulb absent; bursa small, ribs stout Myolaimus Cobb 1920 



Cardiac bulb not valvate; oesophagus idiplogastroid 



Oesophagus without (or with non-valvate, clavate) median swelling Odontopharynx de Man 1912 



Oesophagus with median valvate bulb Diplogaster M. Schultze 1857 



(=Pristionchus Kreis 1932) 

 Ovaries 2 

 Gonads 9 outstretched, Mesonchium reflexed at tips; marine 



Amphid spiral; dots larger laterally; onchia equal; spinneret present (Mesonchium Cobb 1920) 



(=Pepsonema Cobb 1920) 



Amphid circular; striae when present not altered laterally; onchia unequal 



Striae desmodoroid, coarse, plain; amph. behind pharynx, open caudad Paracothonolaimus Schulz 1932 

 Striae none, or not desmodoroid 



Pharyngeal bulb iglobular, set off by constriction; spinneret present Bolbolaimus Cobb 1920 



(=Bulbopharyngiella Allgen 1929) 



Pharyngeal swelling slight, confluent; base of pharynx denticulate Linhomoeus Bast. 1865 



(i.e. subg. Eulinhomoeus de Man 1907) 

 Gonads 9 reflexed (Mesonchium at tips only) 

 Habitat marine; spinneret present; amphid spiral 

 Striae of dots; amphid opposite pharynx, of few winds 

 Subventral onchium small, dorsal acting out; dots unaltered laterally. .. .Chromadorina Fil. 1918 



Subventral & dorsal onchia dhequal, apices axial; dots larger laterally Mesonchium Cobb 1920 



(=Pepsonema Cobb 1920) 

 Striae none or plain 



Head set off by cessation of coarse annulation ; amphid usually multispire . . . Desmodora de Man 1889 

 Head not set off; striae none or very fine 



Male ventral pre-anal supplements tubular, sigmoid, in 2 rows Polysigma Cobb 1921 



Male ventral pre-anal supplements simple, in 1 row Chromaspirina Fil. 1918 



(=Mesodorus Cobb 1920) 

 Habitat not marine 



Spinneret present; amphid spiral, behind pharynx; in fresh water Achromadora Cobb 1913 



Spinneret absent; phasmids present; amphid circular; usually in soil 



Cardiac bulb valvate, oesophagus cephaloboid; onchia 4 Seleneella Rahm 1932 



Cardiac bulb not valvate; oesophagus diplogastroid 



Anterior oesophagus (corpus) without (or with clavate, non-valvate) swelling 

 Cephalic setae 6 or 10; dorsal onch. opposed by ventral onchium or ridge. . . .Butlerius Goodey 1929 



Cephalic setae 6; dorsal onchium opposed by denticles Odontopharynx de Man 1912 



Anterior oesophagus (corpus) ending in valvate median bulb 

 Lips with radiate framework; post, pharyngeal chamber behind onchia. . .Mononchoides Rahm 1928 



Lips without radiate framework; post, pharyngeal chamber none Diplogaster M. Schultze 1857 



( = Pristionchus Kreis 1932) 



