470 PROCEEDINGS HELMINTHOLOGICAL SOCIETY VOL. 2, NO. 1 



Wall of the Pharynx unarmed (for alternative see page 458) 



Cavity not cylindroid nor prismoid, i.e. cavity conoid or irregular in long, section (for alt. see page 474) 

 Oesophagus with median or posterior bulb or swelling, or both (for alternative see next page) 

 Amphid not known or obscure 

 Female not known; spinneret present; cephalic setae present; nema 1% wide; marine 



Cuticle with distinct, anastomosing annules; amphid a transverse slit (Leptonemella Cobb 1920) 



Cuticle without annules; amphid minute, at lips (Catanema Cobb 1920) 



Female known; spinneret none, exc. Dasylaimus 

 Ovaries 2, reflexed; wings present 



Spinneret pres.;phar. denticulate ;oes. without med. bulb ;post. ovary undev.;marine Do0ytotmtu Cobb 1933 

 Spinneret 0; post, pharynx concave-cylind.; oes. with med. bulb; in sheep dung Rhabditoides Goodey 1929 

 Ovary 1 



Gonad 9 outstretched, anterior; cephalic setae 4 Walcherenia de Man 1921 



Gonad 9 reflexed; cephalic setae or minute 



Spinneret present; pharynx denticulate; striae of dots; post, ovary undev. : marine Dasylaimus Cobb 1933 

 Spinneret 0; pharynx not denticulate; oesophagus cephaloboid; not marine 

 Probolae present; amphid at lips; in soil 



Cephalic appendages in 2 circlets Acrobeles Linst. 1877 



Cephalic appendages in 1 circlet Cephalobvs Bast. 1865 



( = Acrobeloides (Cobb) Steiner & Buhrer 1933) 

 Probolae absent; cephalic appendages none or in 1 circlet 



Pharyngeal wall a long, series of elements; onch. 0; vagina directed inward. .Panagrolaimus Fuchs 1930 

 Pharyngeal wall not of serial elements; onch. oft pres. ; vagina directed forward; Turbatricinae 

 Posterior pharynx closed; vulva 75%; vagina less muscular; tail iblunt. . . .Plectonchus Fucbs 1930 



Posterior pharynx open; vulva 65%; vagina muscular; tail slender Turbatrix Peters 1927 



( = Anguillula auctores) 

 Amphid known 



External amphid not spiral, circular nor elliptical 

 Habitat not marine 



Spinneret present; cephalic setae 4; in fresh water; '9 Chronogaster Cobb 1913 



Spinneret none; ovaries 2 



Tail setaceous, 19%;amph. semicirc.;oesoph. with med. bulb;vulva 21%;' 9 ' (Aulolaimoides Micol. 1915) 

 Tail not setaceous, 9-15%; amphid inconspicuous, small or slit-like 



Med. oesoph. bulb confluent in front; post. phar. closed; in decaying matter; ' 9 "... (Cheilobus Cobb 1924) 



( = Rhabdi<ophanes Fuchs 1930) 



Med. oesoph. bulb none; pharynx ovoid; wings 0; amphid a slit; in soil; ~9~. . .Monhystera Bast. 1865 



( = M. dintheriana de Man 1885) 



Habitat marine; cephalic setae present; spinneret present 



Ambulatory tubes forming ventral pre-anal sole; nema S-shape, narrowed in card, reg.; marine; ' 9 ' 

 Oesoph. region hardly swollen; card, bulb faint; cerv. striae all alike. . Notochaetosoma Irwin-Smith 1918 

 Oesoph. region swollen, ovoid; oesophageal bulbs 1 or 2; band of cervical 

 striae accentuated, exc. Tristicochaeta falcatum 



Ventral ambulatory adhesion tubes or setae in 2 rows Drepanonema Cobb 1933 



( = Chaetosoma Clap. 1863) 



Ventral ambulatory adhesion tubes or setae in 3 or 4 rows Tristicochaeta Panceri 1878 



( = Draconema Cobb 1913) 



Ambulatory tubes absent; nema not crooked, not narrowed in cardiac region 



Amphid transverse; pharynx minute; annules plain ;ceph. set. 10, jointed; o* only Leptonemella Cobb 1920 

 Amphid large, folded or shepherd's crook; pharynx obvious; ovaries outstretched 



Pharynx 4-5%, heavy ,tubular;amphid 4-50% body;ceph.set.4,subceph.l2r9~ (Pseitdolella Cobb 1920) 

 Pharynx under 2%, conoid, not heavy; cephalic setae large, long; odontia 6 or 12 



Ovary 1, posterior; cephalic setae 6; odontia 12; vulva 15% (Synodontium Cobb 1920) 



Ovaries 2; cephalic setae 4 ; odontia 6; vulva 45-67% 



Tail clavate; nema shorter, stouter; amphid larger Axonolaimus de Man 1889 



Tail conoid; nema long, slender; amphid smaller Ascnlaimus Ditlev. 1919 



( = Bathylaimus Ditlev. 1918) 

 External amphid spiral, circular or elliptical 

 Female not known 



Habitat soil (possibly marine); spinneret present; amphid spiral; ceph. set. 0. . . .(Amphispira Cobb 1920) 

 Habitat marine 



Amphid multispire; wings 0; annules very fine 



Pharyngeal bulb none; lip region not set off; head truncate-conoid; onch. 3, small Alaimonema Cobb 1920 

 Pharyngeal bulb present 



Head cylindroid; lip region discoid, set off by constriction (Choniolaimus Ditlev. 1918) 



Head hemispherical; lip region not discoid (Amphispira Cobb 1920) 



Amphid circular or monospire; spinneret present 

 Nema cephalated, striae ceasing at constriction 



Pharynx none; head spherical; amphid behind head; nema slender, 1.4%. . . .Cinctonema Cobb 1920 

 Pharynx definite; head hemispherical; amphid on head; nema wider, 3.8% (Micromicron Cobb 1920) 

 Nema not cephalated 



Annules strong, each of 8 tile-like elements; oesphagus compound Dasynemella Cobb 1933 



( = Dasynema Cobb 1920) 

 Annules none; oesophagus not compound 



Cephalic setae 8 or more; onchium minute; amphid minute, at lips Catanema Cobb 1920 



Cephalic setae 4; onchia 0; amphid large, not at lips 



Wing single; amphids on head, large, double, circular, joined dorsally Antomicron Cobb 1920 



Wings 0; amphids behind head, not joined 



Base pharynx faintly cuticularized, without ring; amphid circular Monhysteriella Kreis 1929 



Base pharynx with cuticularring, prongs 2, vertical; amphid monospire. .Cricolaimux Southern 1914 

 Female known 



Ovary 1 (for alternative see next page) 

 Gonad 9 outstretched, anterior ; amphid circular; striae 0, or fine and plain; wings 



Pharynx quadrate; neck under 5%; crystalline bodies lateral; marine (Crystallonema Cobb 1920) 



Pharynx long-conoid; neck 17%; spinneret oresent; in fresh water (Monhystera Bast. 1865) 



(i.e. subg. Monhystrella Cobb 1918) 

 Gonad 9 reflexed ; cephalic setae or minute 



