476 PROCEEDINGS HELMINTHOLOGICAL SOCIETY VOL. 2, NO. 1 



Amphid transverse, curved, wide as head; phar. 7.6%; tail 2%; fresh water; cf only Colpurella Cobb 1920 

 Amphid inconspicuous, small or slit-like; tail over 9%; in soil or decaying material 

 Median oesoph. swelling before isthmus; cardiac bulb valvate; wings single; ' 9 '. .Cheilobus Cobb 1924 



( = Rhabditophanes Fuchs 1930) 

 Median oesoph. bulb absent 



Pharynx closed; amphid a pore, with internal cuticularized tube; wings 2; J Litonema Cobb 1920 



Pharynx open, or with anterior open chamber; wings 0; cf 1 only 



Tail 15%, terminus setaceous; pharynx without cuticularized rods (Monhystera Bast. 1865) 



( = M. dintheriana de Man 1885) 



Tail 8%, conoid; cuticularized rods in pharynx; shed cuticle retained. . . Diphtherophora de Man 1880 



( = Chaolaimus Cobb 1893 

 = Archionchvs Cobb 1913) 



External ampbid spiral, circular or elliptical (for alternative see preceding page) 

 Female not known; spinneret present 



Habitat soil; ceph. set. 0; ceph. cuticle thick, flaps doming vestibule; amph. spiral Pycnolaimus Cobb 1920 

 Habitat marine; cephalic setae present 

 Amphid multispire; annules not coarse; wings absent 



Head cylindroid; lip reg. set off by constriction; pharyng. bulb present. .(Choniolaimus Ditlev. 1918) 

 Head truncate-conoid ;lip reg. not set off ;pharyngeal bulb none;onch.3, minute Alaimonema Cobb 1920 

 Amphid circular, elliptical or monospiral 



Wings 8; annules coarse; oesoph. to isthmus wide, muscular; card, swelling slight Dasynemella Cobb 1933 



( = Dasynema Cobb 1920) 

 Wings 



Cutilarized pharyng. ring basal; ceph. set. 4; <? supplements tubular, 14 Cricolaimus Southern 1914 



Cuticularized pharyngeal ring none 



Spiculum 1, gubernaculum absent; cephalic setae 10; amphid large, oval. .Pelagonemella Kreis 1932 

 Spicula 2, gubernaculum present (Chloronemella?); cephalic setae in circlets of 4 



Striae coarse; amphid minute; length 10 mm. ; width 0.8% Laxonema Cobb 1920 



Striae fine; length under 4 mm. 



Pharyngeal bulb present; amphid at lips; onchia 6, minute Catanema Cobb 1920 



Pharyngeal bulb none; amphid behind pharynx; onchia Chloronemella Allgen 1929 



Female known 

 Ovary 1 

 Gonad 9 outstretched, anterior; amphid circular; wings absent 



Spinneret present; pharynx long-conoid; neck 17%; in fresh water Monhystera Bast. 1865 



(i.e. subg. Monhystrella Cobb 1918) 

 Spinneret absent; neck not over 5%; marine 



Pharynx wide as deep; cardiac swelling faint, elongate; intestine not dark . . Crystallonema Cobb 1920 

 Pharynx tubular; posterior }-J oesoph. a massive bulb; intestine dark colored (Solenolaimus ?) 

 Cephalic setae minute; neck 1.4%; anterior oesoph. fusiform; tail rounded. .Solenolaimus Cobb 1894 

 Cephalic setae often as long as mitreform head is wide; neck 2-5% 



Anterior oesoph. not fusiform; pharynx not eyertible; cf supplements Chromagaster Cobb 1894 

 Anterior oesoph. fusiform;phar. "spear" evertible; cf supplements pres..Siphonolaimus de Man 1893 

 Gonad 9 reflexed; wings often present; not marine exc. rarely Rhabditis 



The ovary posterior, vulva 21%;med.bulb not valvate;amph.semicirc.;mud.. Aulolaimoides Micol. 1915 

 The ovary anterior 



Spinneret pres.; ceph. set. 4; card, bulb or faint; amph. monospire; fresh water (Anonchus Cobb 1913) 

 Spinneret none; setae none, cephalic papillae sometimes setose 

 Oesophageal bulbs median and cardiac; pharynx simple; setae 



Cardiac bulb valvate; amphid at lips, obscure; wings & bursa pres.; ubiquitous Rhabditis Duj. 1845 

 Cardiac bulb not valvate, median valvate; amph. transverse-oval, not at lips; phar. cylindroid 



Dorsal onchium none; bursa present; ectoparasitic on beetle borer Rhabditolaimus Fuchs 1915 



Dorsal onch. small, deepset; bursa 0; in exudate chestnut blight. .(Diplogasteroides de Man 1912) 

 Oesophageal bulb cardiac only, preceded by isthmus; phar. of serial plates; bursa or reduced 

 Head with 6 large odontia; amphid not obscure, often large 



Nema mostly cephalated; cirri 0; amphid circular; soil & fresh water. .Teratocephalus de Man 1876 

 Nema not cephalated; cirri 6; amph. transverse-oval; tail hooked; in bark Chambersiella Cobb 1920 



( = Diastolaimus Rahm 1928) 

 Head entire or 3-parted at lips; nema not cephalated, exc. Acrobeles insubricus; amph. small 



Probolae absent; onchium 0, or 1 inward-pointing Macrolaimus Maupas 1900 



Probolae on head in 1 or 2 circlets 



Circlets of probolae 2, labial and cephalic; amphid a pore near lips (Acrobeles Linst. 1877) 



Circlet of probolae single; amphid often obscure Cephalobus Bast. 1865 



(= Acrobeloides (Cobb) Steiner & Biihrer 1933) 

 Ovaries 2 



Gonads 9 outstretched; cephalic setae present; marine or in brackish soil 

 Amphid multispire; cephalic setae 10, unequal 

 Cardiac bulb ellipsoid; 6 of ceph. set. short; subcephalic setae 4; tail 30%, fine . . Laimella Cobb 1920 



Cardiac bulb slight; 4 of ceph. set. short, tips specialized; tail 7% (Linhomoella Cobb 1920) 



Amphid circular or monospiral; tail not over 18%, not setaceous 



Gland ducts cuticularized, piercing cuticle, yentrad, cerv. & pre-anal. . Halaphanolaimus Southern 1914 

 Gland ducts and pores absent; pharynx minute or none 



Pharynx inone; ceph. set. 10, 4 short, tips specialized; tail 7% (Linhomoella Cobb 1920) 



Pharynx obconqid, when open J-J as wide as head; spinneret sometimes present 

 Cuticularized rings in pharynx 1-3; neck 8-14%; marine & brackish soil (Desmolaimus de Man 1880) 

 Cuticularized pharyngeal rings absent; ventriculus present; marine 



Base pharynx not cuticularized; cardiac bulb oft valvate; head iconoid Cryptolaimus Cobb 1933 

 Base pharynx cuticularized; cardiac bulb valvate; head cylindroid Metalinhomoeus de Man 1907 



(cf. Deltanema Kreis 1929) 

 Gonads 9 reflexed 



Habitat not marine, exc. rarely Rhabditis and Haliplectus (for alternative see next page) 

 Oesophageal bulbs median and cardiac; cephalic setae 0; pharynx tubular (for alt. see next page) 

 Vulva21%;anus81%; amph. semicirc., \ head-width; wings & bursa none (Aulolaimoides Micol. 1915) 

 Vulva 40-94%; in soil etc., in fresh water, and marine 

 Spinneret pres.;amph.monospire,protruding;wings & bursa 0;pores lateral. .Haliplectus Cobb 1913 



