1. f- J * 



Subfamily ACTINOLAIMIx^AE Thome, 1939 

 (Key to the genera modified from Thome, 1939) 



1. Pharynx armed with four large onchia. . ,, . . . Actinolaimus Cobb, 1913 ''.130 

 Pharynx without four large onchia but frequently dentate, corrugated 



or ribbed 2 



2. Vestibule and pharynx with several transverse rows of denticles 



Trachypleura Thorne, 1939 ^'.129 



Vestibule and pharynx without denticles or, if present, they are not 

 arranged in regular transverse rows ... 3 



3. Cuticularization limited to shallow, dish-ljke vestibular plate 

 ........ Mylodiscus Thorne, 1939 



(Contains a single species, M. nanus Thome, 1939) 

 Vestibular cuticularization more complicated, with rod-like processes 

 extending backward to or near the guiding ring I; 



I4. Vestibular cuticularization forming a basket-like chamber or plates j 



guiding ring single? tail blunt ..... . $ 



Vestibular chamber without the above j guiding ring double} tail 

 attenuated BrasilaJjnus Lordello and Zamith, 1958 



(Contains a single species, B. subaquilus Lordello and Zamith, 



1958) 



5. Vestibular chamber basket-like Carcharolaimus Thome, 1939 ^•13? 



Vestibular chamber with flat or rod-like plates 

 Antholalmus Cobb, 1913 P-129 



Qenus Trachypleura Thome, 1939 

 (Key to species from Thome, 1939) 



1. Tails somewhat spicate, short; female c ■ 20 



conformis (Schneider, 1935) Thome, 1939 



Tail attenuated; female c ■ 10 



labyrinthstoma (Cobb, 1893) Thome, 1939 



Antholaimus Cobb, I913 

 (Key to the species from Thome, 1939) 



1. Tail blunt, rounded truncatus Cobb, I9I3 



Tail conoid, acute. . • antarctlcus (Steiner, 1916} Th. k Swang., 1936 



