474 PROCEEDINGS HELMINTHOLOGK'AL SOCIETY VOL. 2, NO. 1 



Amphid wider than long, reniform; lips 3, double, with papillae Margonema Cobb 1920 



Amphid circular or monospiral 



Lips distinct, with distal flaps; ceph. set. 6, stout, jointed; papillae 6. . . .Cytolaimium Cobb 1920 

 Lips absent or confluent 



Oesoph. &lumen with oval enlargement behind eyes ;eyes sometimes none Araeolaimux de Man 1888 

 Oesoph. without median enlargement; eyes 0; cephalic setae 6-10 

 Setae on head 10, shorter 4 specialized at tip; amph. faint multispire. . (Linhomoella Cobb 1920) 



Setae on head 6-8, without specialized tips; amphid circular Linhomoeus Bast. 1865 



Gonads 9 reflexed (for alternative see preceding page) 

 Habitat not marine exc. sometimes Aphanolaimus 



Spinneretabsent; amphid multispire; setae 0; striae of dots; in sand dunes. .Choanolaimus de Man 1880 

 Spinneret present 



Wings present; contour crenate; glands lateral, serial ; amphid monospire. . Aphanolaimus de Man 1880 

 Wings 0, striae not altered laterally; contour not erenate; amphid circular or oval 

 Lips, papillae & setae 0; amphid round; pharynx small, conoid, unarmed Diplohystera de Cillis 1917 

 Lips, papillae & small setae pres.; amph small, oval; phar. closed; onch. basal Tripyla Bast. 1865 



( = Promononchus Micol. 1923) 

 Habitat marine 



Amphid spiral ; spinneret present 



Pharynx with apophyses forward and backward from mid-region 

 Mid-pharyngeal region not denticulate; wings numerous, markings V-shaped. . . .Nunema Cobb 1933 



Mid-pharyngeal region denticulate Halichoanolaimus de Man 1886 



( = Smalsundia Allgen 1929) 



Pharynx without forward apophyses; mid-pharyngeal region not denticulate 

 Wings numerous; neck region "collared"; nema 12-16% wide 



Spicula 2; wings over 50; pharynx narrow Richtersia Steiner 1916 



Spicula unequal, or 1 only; wings 16-32; pharynx capacious, open (Richtersiella Kreis 1929) 



Wings absent, striae if present not altered laterally 



Jaws 3, with backward apophyses and numerous horny teeth anteriorly Demonema Cobb 1894 



Jaws absent, pharynx without apophvses 



Pharynx 2 chambers; ceph. set. 10. oft jointed, tips specialized; striae fine Tripyloides de Man 1886 

 Pharynx 1 chamber; tips setae unspecialized; striae less fine; eyes present 



Cuticular pores none; pharynx with definite bulb Nannolaimus Cobb 1920 



Cuticular pores present; pharvnx without definite bulb Cyatholaimus Bast. 1865 



( = Necticonema Marion 1870) 

 Amphid circular, elliptical or monospiral 



Spinneret absent; cephalic setae 4. stout; tail usually 40% Rhabdocoma Cobb 1920 



Spinneret present 



Oesophagus crenate towards base; calvarium reduced 

 Cervical setae in long, rows; pharynx none; ext. amph. semi-circular (Stenalaimus Marion 1870) 



Cervical setae Phanodermopsis Ditlev. 1926 



( = Galeonema Fil. 1927) 

 Oesophagus not crenate 

 Calvarium present; onchia often 1-3 



The calvarium elaborate, ornate Deontostoma Fil. 1916 



The calvarium a wavy band; often denticles at lips; amphid transverse. .Cylicolaimus de Man 1889 

 Calvarium absent 



Jaws 3, with simple supporting framework Parenoplus Fil. 1927 



Jaws absent 

 Pharynx of 2 chambers 



Chambers of pharynx equal. small; cephalic setae Pseudopelagonema Kreis 1932 



Chambers of pharynx unequal, anterior large; setae 10. often jointed, tips specialized 



Both chambers conoid or irregular in shape Tripyloides de Man 1886 



Both chambers parallel-sided Bathylaimus Cobb 1894 



( = Macrolaimus Ditlev. 1918 

 = Cothonolaimus Ditlev. 1919) 



Pharynx of 1 chamber; setae without specialized tips 



Dorsal pharyng. wall thick, tooth-like; amph. monospire at lips; ceph. set. 4; renette far back 

 Oesoph. glands obscuring junct. of intest.; dorsal phar. element uniform Onchium Cobb 1920 

 Oesoph. glands not prominent; dorsal pharyng. element not uniformly thick, but heavy 



Tooth-like thickening parallel to axis Camacolaimus de Man 1889 



( = Digitonchus Cobb 1920 

 = Acontiolaimus Fil. 1918) 

 Tooth-like thickening bent outward from beginning of vestibule 



Point of "onchium" single Acmaeolaimus Fil. 1918 



Point of Y-shaped "onchium" duplex Ypsilon Cobb 1920 



Dorsal pharyngeal wall not thickened; amphid not at lips; Enoplidae, exc. Aphanolaimus 

 The pharynx open, capacious, walls usually heavily cuticularized; amphid with pocket 



External amphid circular; wall of pharynx irregularly thick (Pandolaimus Allgen 1929) 



External amphid small, transverse;pharyng. wall thin. base with mounds Pelagonerna Cobb 1894 



(cf. Vasculonema Kreis 1928) 

 The pharynx small or very narrow 



Cervical setae absent; cephalic setae 4, in front of amphid Aphanolaimus de Man 1880 



Cervical setae lateral, in short longitudinal series; amphid with pocket 



Gubernaculum present; cf supplementary organ tubular Anticoma Bast. 1865 



Gubernaculum none; cf supplementary organ papilloid Anticomopsis Micol. 1930 



Carity more or less cylindroid or prismoid, i.e. parallel-sided in long, section (for alt. see page 470) 

 Oesophagus with median or posterior bulb or swelling, or both (for alternative see page 477) 

 Amphid not known or obscure (for alternative see next page) 

 Female not known 



Spinneret none;ceph.set.0;phar.closed;oesoph.cephaloboid;neck over 20%;in swamp Litonema Cobb 1920 

 Spinneret present; setae on head numerous; neck under 5%; amphid small, near lips; marine 



Pharyngeal bulb present; striae none; length 3-4 mm. ; onchia(?) 6, minute (Catanema Cobb 1920) 



Pharyngeal bulb none; striae annulating the cuticle; length 10 mm (Laxonema Cobb 1920) 



Female known; spinneret none exc. Rhabdolaimus; not marine; phasmids usually present 



