COBB: A KEY TO THE GENERA OF FREE-LIVING NEMAS 467 



Oesophagus plain, i.e. without median or posterior bulb or swelling (for alternative see page 465) 

 The teeth equal in size, usually mobile radially (for alternative see next page) 

 Stroke of teeth outward; amphid usually not obscure 



External amphid spiral, circular or elliptical; spinneret present (Eleutherolaimus ?) 

 Armature of 2 teeth ;ceph. set. 4 ;amph. monospire.in front of setae;d" only Diodontolaimus Southern 1914 

 Armature of 6 or 12 odontia 



Odontia 3-jointed, heavy ;phar. cylind.;onch. dorsal ;am ph. round-multispire; ~9 Scaptrella Cobb 1917 

 Odontia not jointed 



Amphid "folded" or shepherd's crook; ~9~ Odontophora Butsch. 1874 



( = Trigonolaimus Ditlev. 1918 

 = ConolaimusFil. 1918) 



Amphid circular or elliptical, sometimes obscure; cephalic setae 4 



Pharynx obscure; odontia small; lab. set. 6, setae long; striae coarse; ' 9 ' Stephanolaimus Ditlev. 1918 

 Pharynx obvious; odontia larger; labial and subcephalic setae 0; cf only 



Striae of dots; amphid transverse, open caudad Apodontium Cobb 1920 



Striae plain; amphid circular Eleutherolaimus Fil. 1922 



External amphid not spiral, circular nor elliptical; spinneret pres. exc. Ironus and Parironus 

 Cardiac bulb slight ; striae of dots ; amphid a transverse slit near lips ; ' 9 ' 



Dots of striae larger laterally, in longitudinal rows (Chromadarella Fil. 1918) 



Dots of striae not altered laterally (Prochromadorella Micol. 1924) 



Cardiac bulb none; striae none, or plain and very fine 

 Odontia 6, sometimes dentate; amphid "folded" or crook-shaped; ~9~ 



Amphid opposite basal portion of pharynx; odontia less developed Axonolaimus de Man 1889 



Amphid opposite anterior portion of pharynx; odontia more developed Odontophora Butsch. 1874 



( = Trigonolaimus Ditlev. 1918 

 = ConolaimusFil. 1918) 

 Odontia or onchia 3; amphid transverse, with internal pocket; ovaries reflexed 



Armature 3 awl-shaped onchia, protrusile forward; pharynx 0.5%; ' 9 ' (Fimbrilla Cobb 1905) 



( = Fimbria Cobb 1894) 

 Armature 3 heavy odontia; pharynx tubular, l-4 ( : ' c ; Ironinae 



Lips expanded, denticulate, 6; tail 2% ; spinneret ventrad; 9 ' Trissonchulus Cobb 1920 



Lips not expanded; tail 5% or more; spinneret not ventrad; ' 9 ' 



Spinneret none; pharynx 2-4%; dorsal tooth duplex; in fresh water and soil Ironus Bast. 1865 



Spinneret present (in Parironus rudimentary or none); marine 

 Cephalic setae or papilloid; odontia not duplex; pharyngeal swelling slight 



Pharyngeal wall thin; pharynx 3%; nema 3 mm Dolicholaimus de Man 1888 



Pharyngeal wall thick; pharynx 1.1%; nema 2-7 mm Thalassironus de Man 1889 



Cephalic setae present 

 Odontia duplex; phar. 2.7%, bulb set off by constriction; ceph. set. 6,subceph.4../roneifa Cobb 1920 



Odontia not duplex; pharynx 1-1.6%, swelling slight; cephalic setae 10 Parironus Micol. 1930 



Stroke of teeth inward; amphid known, in Enoplidae with internal pocket and often obscure 

 External amphid not spiral, circular nor elliptical; ovaries reflexed 



Ovary 1, post.; phar. bulb strong; "palps" labial ;onch. 3, at summit of apophyses Gammanema Cobb 1920 

 Ovaries 2; wings absent; amphid with internal pocket; Enoplidae 



Calvarjum a band with undulating margins; glands lateral; odontia large Fiacra Southern 1914 



Calvarium absent 



Onchia 3, awl-like, protrusile forward, like bristles around open mouth Fimbrilla Cobb 1905 



( = Fimbria Cobb 1894) 

 Onchia not awl-like 

 Lips confluent, bearing 6 (or 3 duplex) odontia 



Pharynx narrow; onchia 0; odontia probaby 6 Tubolaimella Cobb 1933 



Pharynx conoid; onch. 3, midway , alternating paired odontia . . Rhabdodemania Baylis & Daubney 1926 



( = Demania Southern 1914) 

 Lips distinct, 3; armature heavy 

 The lips large, conoid, as high as broad; jaws 3 



Mandibles 2-clawed; lips radially striate; spicula long, striate Enoploides Saveljev 1912 



Mandibles absent; lips not striate; tooth midway on onchial framework . . . Enoplolaimus de Man 1893 

 The lips not conoid, nor as high as broad 

 Armature 3 short flattish acute onchia, doming the ismall pharynx .... Triodontolaimus de Man 1893 



Armature of 3 jaws within the pharynx, anteriorly 2-pointed Enoplus Duj. 1845 



( = Enoplostoma Marion 1870) 

 External amphid spiral, circular or elliptical 

 Female not known 

 Amphid monospire, transverse; lips 4; cephalic setae 4; c? supplements 8-12, tubular 



Striae very fine; pharynx conoid; onchia 3; labial papillae 2 Dagda Southern 1914 



Striae coarse; phar. cylind.; onch. 2, lateral orsubventral; lab. papill. 4 Diodontolaimus Southern 1914 

 Amphid multispire; d* supplements ichromadoroid 



Pharynx unarmed; lips 6, grasping organs, with longitudinal cuticular ribs Dispira Cobb 1933 



Pharynx armed, bulb strong; often nemativorous; cf supplements chromadoroid 

 Mandibles 3, split exc. at tips, distal hooks 3, subordinates 2; phar. 1 chamber. .Synonchium Cobb 1920 

 Mandibles 0; phar. 2 chambers; onchia 3, midway, with backward apophyses. . Trogolaimus Cobb 1920 

 Female known 



Ovary 1 ; amphid circular or monospiral (for alternative see next page) 



Gonad 9 post.;pnch.3, on apophyses ;phar.bulb strong ;spinneret pres.;marine Gammanema Cobb 1920 

 Gonad 9 anterior 

 Spinneret none; wings none; labial "palps" 6, small; marine; ~9 



Amphid large, raised centrally; tail with thorn-like setae (Zanema Cobb 1920) 



Amphid small, not projecting; tail without setae (Crystallonema Cobb 1920) 



Spinneret present 

 Cephalic setae usually or papilloid; ovoviviparous or viviparous; in gills of land crabs 



Pharynx small, of 2 chambers; cephalic setae 10, often papilloid. (Monhystrium Cobb 1920) 



Pharynx large, open, of 1 chamber; cephalic setae 0; wings none Tripylium Cobb 1920 



Cephalic setae present; ovary outstretched; marine 



Lips thick, with 3 projecting finger-like "odontia"; wings up to 32 on head (Xyala Cobb 1920) 



Lips 6, very thin, each with 3 parallel-sided cuticularized ribs (Daptonema Cobb 1920) 



(cf. Theristus Bast. 1865) 



