478 PROCEEDINGS HELMINTHOLOGICAL SOCIETY VOL. 2, NO. 1 



Calvarium present; setae 8, near base of pharynx; eyes present Gullmarm'.a Allgen 1929 



Calvarium absent; setae minute, around mouth; eyes 0; pharynx small, tubular. .Fimbriella Allgen 1929 

 Female known (for alternative see preceding page) 

 Ovary 1, anterior 



Ceph. set. 4; pharynx large, open; spinneret present; spicula 2-jointed(?); marine. ..Filipjeva Ditlev. 1928 

 Ceph. set. or papilloid; pharynx none or narrow; spinneret usually none; ~9 



Pharynx a tube reaching halfway to nerve ring; in soil Gymnolaimus Cobb 1913 



Pharynx closed, or marked by reduced spear, not over J distance to nerve ring 



Nema free-living, marine; spinneret doubtful; pharynx none or closed Litotes Cobb 1920 



Nema parasitic in insects; spinneret 0; adult spear reduced, base 3-parted. . (Aphelenchulus Cobb 1920) 

 Ovaries 2 

 Gonads 9 outstretched; spinneret present; marine 



The ovaries extending backward; winge 10-12; vulva 45% Porocoma Cobb 1920 



The ovaries opposed; wings 



Annules none or not coarse; amphid not saccate, far back; nema not wide. . . . Anoplostoma Butsch. 1874 

 Annules coarse; amphid saccate; nema wide; cephalic setae 4 



Number annules 17, secreted annules prominent, separated; head small .. Desmoscolex Clap. 1863 

 Number annules 32-91, secreted annules 0; head concave-quadrate pyramidal. .Tricoma Cobb 1894 



( = Quadricoma Fil. 1922) 

 Gonads 9 reflexed 



Spinneret none; wings 0; pharynx 2.5-3%, tubular; tail rounded, under 2%; in soil. .Isolaimium Cobb 1920 

 Spinneret present 



Habitat freshwater; lips thick; pharynx closed; amphid small; onch. small, deepset (Tripyla Bast. 1865) 



(=Promononchus Micol. 1923) 

 Habitat marine 



Annules 17,secreted annules prominent;amph.saccate;nema wide;ceph.set.4. .Desmoscolex Clap. 1863 

 Annules none; amphid not saccate; nema less than 5% wide 

 Dorsal pharyngeal wall bent inward at lips,onchium-like;ceph.setae 10. .(Asymmetrella Cobb 1920) 



Dorsal pharyngeal wall not onchium-like; cephalic setae Angustinema Cobb 1933 



Amphid known (for alternative see preceding page) 



External amphid not spiral , circular nor elliptical (for alternative see next page) 

 Female not known; Enoplidae (Trileptium ?) 



Head mitreform, set off by constriction; wings 6-8; spinneret doubtful; marine Xennella Cobb 1920 



Head not mitreform; spinneret often absent 



Ceph. set. 0: ext. amph.wide,curved;phar.tubular,halfway to nerve ring ;fresh water Colpurella Cobb 1920 

 Ceph. set. present; amphid small, or long and narrow; marine 



Amphid narrow,many head-widths long ;neck 40% ;ceph.set.4-8;tail setaceous Halalaimoides Cobb 1933 

 Amphid small, transverse-oval; neck 25% or less 



Neck 25%;onchium no ne;ceph. setae 6 .small, inconspicuous ;spinneret present. . Vasculonema Kreis 1928 



(cf. Pelagonema Cobb 1894) 



Neck 12%; onchium dorsal; cephalic setae 10, conspicuous; labial setae 6 . . . . Trileptium Cobb 1933 



( = Trilepta Cobb 1920) 

 Female known 

 Ovary 1 ( anterior 



Gonad 9 outstretched ;pharynx closed;ceph.set.papilloid;spinneret doubtful ;marine. .Litotes Cobb 1920 

 Gonad 9 reflexed; spinneret present; external amphid a transverse slit, not at lips; not marine 



Onchia 0; amphid far behind the quadrate pharynx; in fresh water Prismatolaimus de Man 1880 



Onchium minute, deepset; amphid opposite pharynx; in soil about roots 



Pharynx conoid when open; amphid opposite base of pharynx (Trischistoma Cobb 1913) 



Pharynx a long tube, amphid opposite its anterior end, with pocket Cryptonchus Cobb 1913 



( = Dilletsenia Micol. 1925) 

 Ovaries 2; marine exc. Monhystera 

 Gonads 9 outstretched 

 Spinneret absent 



Habitat marine; amphid long-oval, on large triangular plate Didelta Cobb 1920 



Habitat not marine; amphid a transverse slit; in soil about roots Monhystera Bast. 1865 



(=M. dintheriana de Man 1885) 

 Spinneret present 



Mouth opening ventrad;wing duplex ;amph. big, bent, dorsal arm the longer (Campylaimus Cobb 1920) 

 Mouth opening axial, terminal; wings none exc. sometimes Pseudolella 

 Annules coarse; amphid saccate; nema wide; cephalic setae 4 



Number of annules 17, secreted annules prominent, separated; head small. . Desmoscolex Clap. 1863 

 Number of annules 32-91, secreted annules 0; head concave-quadrate pyramidal . . Tricoma Cobb 1894 



( = Quadricoma Fil. 1922) 

 Annules none, striae fine; amphid not saccate; nema slender 



Amphid small, opening transverse with internal pocket, far back (Anoplostoma Butsch. 1874) 



Amphid shepherd's crook, dorsal arm the longer 



Length of amphid extreme, sometimes exceeding neck; eyes (Pseudolella Cobb 1920) 



Length of amphid not over 1 head-width, loop-shaped; eyes 2, sometimes none 

 Oesophagus & lumen widened between eyes and nerve ring;pharynx obvious Coinonema Cobb 1920 

 Oesophagus & lumen not widened; pharynx like oesophagus. . . Araeolaimoides (de Man) Fil. 1918 

 Gonads 9 reflexed 

 Spinneret absent; amphid with internal pocket 



Cephalic setae 0; pharynx 2-3%, tubular; tail rounded, under 2%; in soil Isolaimium Cobb 1920 



Cephalic setae 10, subcephalic many; marine Platycomopsis Ditlev. 1926 



( = Dact V lonema Fil. 1927) 

 Spinneret present 



Habitat freshwater; amphid usually small or inconspicuous 



Pharynx wide.domedby thin lips ;onch.0;amph.transverseslit,far back. .Prismatolaimus de Man 1880 

 Pharynx closed, lips thickionch. minute, deepset ;external amphid round or oval. .(Tripyla Bast. 1865) 



( = Promononchus Micol. 1923) 

 Habitat marine 



Cephalic setae none or papilloid; external amphid narrow, transverse (for alt. see next page) 

 Amphid J head-width; cuticle i radius, annules coarse, markings rod-like. .(Actinonema Cobb 1920) 

 Amphid f head-width or less, with internal pocket ; cuticle less thick ; phar. with lumen ; Enoplidae 

 Eyes 2; protrusile pharyngeal ribs none Illium Cobb 1920 



