460 PROCEEDINGS HELMINTHOLOGICAL SOCIETY VOL. 2, NO. 1 



Spear plain, i.e. not bulbed at base (for alternative see page 458) 

 Oesophagus plain, i.e. without median or posterior bulb or swelling 

 Amphid known 



External amph.reniform; dorsal pnch. small, at spear base; ovary ant.; not marine Enoplocheilus Kreis 1932 

 External amphid circular, elliptical or monospiral 

 Spinneret absent; anus reduced; parasitic in beetles 

 Pharyng.bulb strong.head swollen; spear 1.5%; junct.oesoph.& intest. indef. ;~9 (Rhabdonchus Cobb 1933) 



Pharyng. bulb none; spear vestigial; in beetle, Passalus; '9 Chondronema Christie & Chitwood 1931 



(= Uracanthus Dies. 1861) 

 Spinneret present; marine 



Annules coarse exc. on head ; onch. spear-like, axial ; body set. in long, rows ; ~ 9 ~ Aculeonchus Kreis 1928 

 Annules none or fine; head not expanded; cephalic setae 4 



Striae of dots, larger laterally; amph. multispire; spicula 2-jointed; ~9~. .Dorylaimopsis Ditlev. 1918 



( = Xinema Cobb 1920) 

 Striae 0; amph. monospire; spicula entire; junct.oes. & intest. obscured by glands; eyes present 



Spear 0.3%, a thickening of dorsal phsryngeal wall; ovaries 1 or 2, reflexed (Onchium Cobb 1920) 



Spear more obvious, 1.5%; ' S ' Onchulella Cobb 1920 



Amphid unknown or obscure 



Female not known; spear a small prod at lips; marine Rhinonema Allgen 1927 



Female known 



Spinneret present; ovaries 2; marine 

 Calvariumsubcuticular; spear long, slender; set. on head long; nema 6 mm. Thoracostomopsis Ditlev. 1918 



Calvarium none; head not suddenly narrowed; spear short; ovaries reflexed (Onchulella Cobb 1920) 



Spinneret absent; ovary 1; not marine 



The female saccate, sausage-shaped; vulva terminal, ovary reflexed; in beetles Allantonema Leuck. 1884 



(=Tylenchomarphus Fuchs 1914) 



The female ielongate, usually not slender; vulva posterior, ovary anterior 



Ovary outstretched; anus present; spear a mere prod, reduced in a"; wings O...Iotonchium Cobb 1920 

 Ovary reflexed exc. Rhabdonchus; anus none or reduced; parasitic in insects 



Spear long, slender, in muscular bulb, head swollen; junct. oes. & intest. indef. .Rhabdonchus Cobb 1933 

 Spear vestigial, minute or none; pharyngeal bulb absent 



Mouth and spear absent; in beetles, weevils, etc (Bradynema Strass. 1892) 



Mouth and spear present in young 9 only; in beetles, frit fly, etc. 



' Vulva degenerating; 9 free-living ;bursa pre-anal;in Passalus Chondronema Christie & Chitwood 1931 



(= Uracanthus Dies. 1861) 

 Vulva remaining functional; adult 9 parasitic; gubernaculum small 



Anus none or vestigial; in cucumber beetle, Diabrotica Howardula Cobb 1921 



Anus persisting; in frit-fly, Oscinella (Tylenchinema Goodey 1930) 



Oesophagus with median or posterior bulb or swelling, or both 

 Amphid nc 



r ._ not known or obscure 



Spinneret present; cardiac swelling slight; spear a small prod at lips; J (Rhinonema Allgen 1927) 



Spinneret absent; cephalic setae 



Nema parasitic, saccate female; vulva terminal; in beetles, etc.; '9 (Allantonema Leuck. 1884) 



(=Tylenchomorphits Fuchs 1914) 

 Nema free-living 



Armature a minute labial prod; expanding headsuddenly truncate; vulva88%;~ 9 lotonchium Cobb 1920 

 Armature an obvious spear 



Spear closed, bent dorsad at tip when extruded; '9 (Campydora Cobb 1920) 



Spear open, a hollow passage; not bent at tip 



Lips petaloid, lip reg. expanded, discoid ; oesoph. dorylaimoid ; spear small ; ' 9 ' Antholaimus Cobb 1913 

 Lips 0; median bulb valvate, with outlets of 3 glands; junction oesoph. & intestine indefinite; ~9 



Gubernaculum and bursa present Aphelenchus Bast. 1865 



(=*Isonchus Cobb 1913) 



Gubernaculum and bursa absent Aphelenchoides Fischer 1894 



( = Seinura Fuchs 1931 

 *=Parasilaphelenchus Fuchs 1930 

 =Pathoaphelenchus (Cobb) Steiner 1931) 

 Ampbid known 



External amphid spiral, circular or elliptical (for alternative see next page) 

 Spinneret present; amphid labial, spiral; "spear" filling posterior pharynx; marine 



Width of nema 3.5%; pharyngeal bulb definite; ' 9 ' Onyx Cobb 1891 



Width of nema 7%; pharyngeal bulb faint; J Oistolaimus Ditlev. 1921 



(cf. Onyx Cobb 1891) 



Spinneret absent; amphid circular or elliptical 



Anus none;setae 0; pharyng.bulb strong; junct.oes.&intest. indef.; in beetles; ~ 9 Rhabdonchiu Cobb 1933 

 Anus present; nema free-living 



Cephalic setae 10, Siphonolaimus sometimes 0; amphid circular 

 Habitat marine ;"spear" evertiblephar.lining;nema5-10mm.;neck4%; ~ 9 Siphonolaimus de Man 1893 



Habitat moist soil; spear tooth-like; nema 0.85 mm.; neck 16% Odontolaimus de Man 1880 



(=Neonchus Cobb 1893) 

 Cephalic setae 



Spear bent dorsad at tip when extruded; amphid small, oval, at lips; '9 Campydora Cobb 1920 



Spear not bent at tip 



Med.oes.bulb 0;nema dorylaimoid;lab.papillae 6,cepb.6;ovaries 2 (Tylolaimophorus de Man 1880) 

 Med. oes. bulb valvate; nema tylenchoid; papillae 0; amphid oval, near lips 

 Junction of oesophagus and intestine definite 



Gubernaculum and bursa absent; tail often with mucron; ~9 Paraphelenchus Micol. 1925 



Gubernaculum small; bursa without ribs; tail slender, long-conoid; ~9~ Psilenchus de Man 1921 

 Junction oesoph. & intestine indefinite; oes. gland outlets at med. bulb; tail short; ~9 



Bursa and gubernaculum present Aphelenchus Bast. 1865 



(=Isonchus Cobb 1913) 



Bursa and gubernaculum absent Aphelenchoides Fischer 1894 



( = Seinura Fuchs 1931 



=Parasitaphelenchus Fuchs 1930 



=Pathoaphelenchus (Cobb) Steiner 1931) 



