13U. 



fiGnus Xiphinema Cobb, 1913 

 (Key to the species from liordello, 1955) 



1. Ovary one 2 



Ovaries two 5 



2. Tail rounded and short ensiciilifer'.mi (Cobb, 1893) Thorne, 1939 



Tail elongated, conoid or digitate 3 



3. Two pairs of caudal papillae present Ii 



Three pairs of caudal papillae present radicicola Goodey, 1936 



I4. Tail elongate, amphids narrow and long chambersi Thorne, 1939 



Tail distinctly digitate, amphids wide and short 

 . brasiliense Lordello, 1951 



5. Tail short and rounded 6 



Tail elongate, conoid, subconoid or digitate 9 



6. Lip region set off by constriction 7 



Lip region continuous .«.. 8 



7. Small species (I.6I6 iran.)» V = UO.O^, oesophagus short, (b = 6) 



grande Steiner, I9IU 



Large species (U«0, mm.), V = 60^, oesophagus very long (b = 2) 

 makrodorum (Vanha, 1893) Thome, 1939 



8. Small species (0.8 mm.) obtusum Cobb, 1939 



Large species (li.l mm.) . -. . . rot\indatum Stekhoven & Teunissen, 1938 



9. Lip region expanded linenm (Grube, 18U9) Thome, 1937 



Lip region not expanded 10 



10. Head truncate truncatum Thome, 1939 



Head more or less rounded, not truncate -11 



11. Length 3.U - U.O irm. or much larger (8,9U mm.) 12 



Length 2.60 mm. or less Ill 



12. V = 38.9^ index Thome & Allen, 1950 



V = U7.8 % 13 



13. Length 8,9U mm cylindri caudatum Stekhoven & Teunissen, I938 



Length .1+0 mm ... . diversicaudatum (Micoletzky, 1927) Thome, 1939 



lU. V = 51.0 - 51|.0^. . americanum Cobb, 1913 



V = 29.8 - \xlM 15 



15. Tail subconoid or digitate, not vntrally arcuate 16 



Tail distinctly elongated, more or less deeply ventrally arcuated , 17 



