138. 



Subfajnily DORYLAIMIME 

 (Key to the genera) 



1. Lips with cuticularized pieces about vestibule 



Puui^entus Th. j:- Gwan^., 1936 P.13S 



Lips without cuticularized pieces ..... 2 



2o Lip region broadly expanded, disc-like Discolaimus Cobb, 1913 P.lljO 



Lip region only about as wide as the adjacent neck. ........ 3 



3. Anterior portion of esophagus very slender, set off by alteration in 



tissues .................. Discolaiiriuni Thome, 1939 P.lhO 



Anterior portion of esophagus normal, not set off , . l\. 



Uo Spear without guiding ring 5 



Spear with guiding ring ............... 6 



5- Anterior portion of spear distinctly curved 



. Drepanodorus Altherr, 195U 



(Contains a single species, D. leptoceohalus Altherr, 195h) 

 Anterior portion of spear not curved. . Aporcelaimus Th. & Swang., 1936 P.lltl 



6» Inner circle of papillae on outer margin of head 7 



Inner papillae not marginal 8 



7<. Muscular ridge encircling entrance to vestibule 



■ Chrysonema Thorne, 1929 P.13o 



Perioral muscular ridge absent. Tho mia Meyl, 195ii ?.li!3 



8. Spear guiding ring double, tails of sexes similar, obtuse or bluntly 



conoid. . <, . , , Labronema Thorne, 1939 P.1U2 



Spear guiding ring not double or, if so, the male tail is short and 

 rounded and that of the female elongated or filiform. ....... 9 



9. Anterior portion of spear distinctly curved 



o . Drepanodorus Altherr, 195^4 



(Contains a single species, D. leptocephalus Altherr, 195U) 

 Anterior portion of spear not curved Dorylaiirus Dujardin, 181;5 P.lhi; 



Genus Chrysonema Thome, 1929 

 (Key to the species from Thome, 1939) 



1, Length about ^.h mjn . , . . , abyss inica Filipjev, 1931 



Length near 2.0 mm or less 2 



2. Length near 2.0 mm aurum Thorne, 1929 



Length near 1.0 mm thorni Filipjev, 1931 



