Siipsrfamily D iRYLAIMOIDPA Thome, 193ii V;^.\ *""^^'' J '^j 

 {Y.eY to the families) X'*'!:--^ *'\^^<S^/ 



.♦ -J- vy 



1. Esophagus with enlarged posterior third or more 2 



Esophagus with only a pyriform or elongate basal bulb U 



2. Enlarged portion of esophagus surrounded by a sheath of soiral muscles 



, BKLONDIRIDAE Thorne, 1939 P. 122 



Enlarged portion of esoohagus not surrounded by muscular sheath . . 3 



3- Amphids with obscure slit-like apertures; common 



'. D0RYLA3MIDAE de Man, I876 P. 121 



Amphids with moderately large to large circular aoertures; rare (in 



Russia) OPAILAIMIDAE Kirjanova, 1951 P. 121 



U. Amphid apertures obsciore, slit-like; testes two; an adanal pair of 



supplements present LEPTONCHIDAE Thorne, 193$ P. 1^8 



Amphid apertures ellipsoidal, conspicuous; testis one; adanal pair of 

 supolements absent DIPHTHEROFHORTDAE Thome, 193$ P. 162 



Family OPAILAII>''IDAE Kirjanova, 1951 

 (Key to genera) 



Large circular amphids Opailaimus 



(Contains a single species (0. mirus . ) 

 Smaller circular amphids and bearing peculiar forward-pointing ex- 

 trusions of the cuticle on the head . . . . Ottolaimus , Kirjanova, 1951 



(Contains a single species 0. otiosus .l 



Family DORYLAIMIDAE de Man, 18? 6 

 (Key to the subfamilies from Thome, 1939) 



1. Pharynx armed with a mural tooth NYGOLAIKiINAE Thorne, 1935 P. 126 



Pharynx arm.ed with an axial spear 2 



2. Vestibule and pharynx heavily cuticularized, often dentate 



ACTINOLAIMNAE Thorne, 1939 P. 129 



Vestibule and pharynx not heavily cuticularized 



3 



3. Spear greatly attenuated LONGIDORINAE Thorne, 1935 P. 133 



Spear not greatly attenuated, or if so f rarely) the basal portion of 



the esophagus is not set off by a constriction 1; 



U. Spear with simple basal extensions DORYLAIMINAE Filipjev, 1928 P.I38 



Spear compound, with knobed basal extensions or flan^res 

 Ti'l-l'lJCilOLAlt' INA^' Filipjev, 193U P. 157 



