458 PROCEEDINGS HELMINTHOLOGICAL SOCIETY VOL. 2, NO. 1 



Tail under 10%; vulva 60%; ceph. set. 1 head-width long; internal amphid not conspicuous 

 Ceph. set 10, cervical long, bunched, in & 2 flat ones at amphid; tail 3%, conoid. .Platycoma Cobb 1894 

 Ceph. set. 4 (6?), other setae 0; nema cephalated by contraction; tail slender, 9%. . . Acoma Steiner 1916 

 Spinneret present (for alternative see preceding page) 

 Habitat not marine (Aphanolaimus ?); contour often crenate 



Amphid obscure,small;pharynx narrow;onch.deepset;ceph.set. 6-10, oft papilloid. . .(Tripyla Bast. 1865) 



( = Promononchus Micol. 1923) 

 Amphid distinct, circular or spiral; pharynx none or closed; ceph. set. 6, rarely 4 or 



Position of amphid i-2 head-widths back Aphanolaimus de Man 1880 



Position of amphid 3-4 head-widths back Bastiania de Man 1876 



Habitat marine 



Ambulatory tubes hollow; body setose, annulated 



The amphid not saccate; ambulatory tubes ventral ; setae not dense. .Notochaetosoma Irwin-Smith 1918 

 The amphid saccate; annules coarse, 17-91; nema broad 



Body setae not dense; secondary annules secreted, prominent (Desmoscolex Clap. 1863) 



Body setae dense, set along annules; junction oesoph. & intestine indefinite. . . . (Greeffiella Cobb 1922) 



( = Trichoderma Greeff 1869) 



Ambulatory tubes absent; body not densely setose; not annulated exc. Stephanolaimus 

 Wings 50;nema broad, 16% ;neck "collared" ;amphid spiral ;pharynx small.. .Richtersia Steiner 1916 

 Wings if present not numerous; nema slender, under 5% 



Odontia 6; ceph. set. 4, long; lip reg. discoid; gland ducts oft projecting. .Stephanolaimus Ditlev. 1918 

 Odontia 0; cephalic setae not longer than head is wide 



Gland ducts cuticularized, pores cervical & pre-anal; striae coarse . . Halaphanolaimus Southern 1914 

 Gland ducts and pores none, or not cuticularized 



The amphid multispire; cephalic setae 16, 1 head-width long; in sand . .Nannolaimus Cobb 1920 

 The amphid not multispire 



Amphid at lips, transverse-oval, with large gland; eyes with lenses lonema Cobb 1920 



Amphid not at lips; eyes none exc. Leptosomatum 



Anterior part of oesoph. the wider; cervical setae 0; amphid irregular. . .Southernia Allgen 1929 

 Anterior part of oesoph. not wider; amphid with internal pocket 

 Oesophagus crenate posteriorly 



Calvarium none; labial tubercles none Stenolaimus Marion 1870 



Calvarium in front of ceph. set., margin irregular; labial tubercles 3 Klugea Fil. 1927 



(=Phanodermopsis Ditlev. 1926, in part) 

 Oesophagus not crenate posteriorly 



Cephalic setae 0; pores on anterior half of neck; tail rounded Leptosomatum Bast. 1865 



Cephalic setae present; pores on neck absent 



Setae on neck none; cephaljc setae 10, 1 head-width long Leptosomella Fil. 1927 



Setae on neck in lateral series; amphid small 



Gubernaculum present; c? pre-anal ventral supplement tubular Anticoma Bast. 1865 



Gubernaculum none; cf pre-anal ventral supplement papilloid. .. (Anticomopsis Micol. 1930) 



PHARYNX PRESENT (for alternative see page 454) 



Wall of the Pharynx armed (for alternative see page 470) 

 Armature spear-like or apparently so (for alternative see page 461) 



Spear bulbed; cephalic setae usually 0; amph. oft obscure; spinneret 0; not marine exc. Siphonolaimus (pg. 460) 

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

 Female not known spear with retrorse points midway, base 3-lobed ;bursalobed. .Ecphyadophora de Man 1921 

 Female known; ovary 1 

 Gonad 9 reflexed 



Habit free-living; spear (dorso-ventral view) arrow-headed; ovary posterior. . Pharetrolaimus de Man 1921 

 Habit parasitic in beetles, etc.; ovary anterior 



Nema saccate; mouth none, organs degenerated; vulva terminal (Allantonema Leuck. 1884) 



( = Tylenchomorphus Fuchs 1914) 

 Nema not saccate; anus none or vestigial 



Spear none; parasitic in beetles, weevils, etc (Bradynema Strass. 1892) 



Spear present in young 9 only ; in cucumber beetle, Diabrotica Howardula Cobb 1921 



Gonad 9 outstretched; mostly parasitic 



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



Anus present; spear present, in Aphelenchulus reduced; traces median bulb sometimes present 

 Junction oesoph. & intest. definite; anterior oes. fusiform, isthmus at nerve ring; in or about plants 



Habitat crop plants; head of 8 sectors; terminus of tail straight Neotylenchus Steiner 1931 



Habitat bladders of Fucus, or among marine algae; head of 6 sectors; tail hooked. . Halenchus Cobb 1933 

 Junction oesophagus and intestine indefinite 

 Spear with 6 basal lobes; oesoph. isthmus at nerve ring; in decaying vegetation. . Hexatylus Goodey 1926 



Spear with tripartite base; renette body length; parasitic in insects Aphelenchulus Cobb 1920 



Oesophagus with median or posterior bulb or swelling, or both 

 Female not known ; spear tripartite at base 



Cephalic setae 4, 1 head-width long; oesoph. swellings med. & card.; bursa striate. .Eutylenchus Cobb 1913 

 Cephalic setae or papilloid 



Spear with retrorse points midway, 3-lobed at base; bursa small, lobed Ecphyadophora de Man 1921 



Spear without retrorse points midway ; oesophagus without median bulb 



Pharyngeal bulb O.cardiac i neck length ;ceph.set.0;nema 5% wide;bursa 0. . Tylencholaimellus Cobb 1915 

 Pharyngeal bulb pres.;ceph.set.6,papilloid;nema 9% wide;tail short .rounded. .Brachynemella Cobb 1933 



( = Brachynema Cobb 1893) 

 Female known 



Ovaries 2; cephalic setae 0; spear with tripartite base (for alternative see next page) 

 Gonads 9 outstretched (for alternative see next page) 



Median oesophageal bulb absent ; spear 3-pronged at base ; in sandy soil . . . ( Tylolaimophorus de Man 1880) 

 Median oesophageal bulb present; spear 3-lobed at base 



Junction oesoph.& intestine indefinite ;annules plain;tail rounded.with bursa. . Hoplolaimus Daday 1905 

 Junction oesoph. & intestine definite, exc. sometimes Tylenchus 

 Spear-guide wide as head, forming cuirasse or helmet; bursa none; testes 2..Nemonchus Cobb 1913 



