Pnrns. K:6 



KKf TO THE SPECIES OF XIFFIINIJiriA COBB, 1913 

 (After LuFTTJbW 



Females 



1. One ova.ry « 2 



Two ovaries (the anterior one reduced and obscure in X. krugi ) 5 



2. Tail long (more than four times body width at anus) 



-' chainbersi Thorne, 1939 



Tail short (less than fotir times body width at anus) 3 



3. Tail hemispherical ^X. ensiculiferum (Cobb, 1893) Thorne, 1939 



Tail mammillate (digitate) 1|, 



)4. T;to pairs of caudal papillae ^X. brasiliense Lordello, 1951 



Three pairs of caudal papillae ^X. radicicola Goodey, 1936 



5. Tail long (mere than four times body width ar anus) 6 



Tail short (less than fom- times body width at anus) 7 



6. V ^ 29-32^; seven pairs of caudal papillae—X. insigne Loos, 19[t9 

 V = h7%', three to five pairs of caudal papillae~X. hallei n. sp. 



7. Tail hemispherical or mfjiL-nillate (digitate) 8 



Tail conical 13 



8. Tail hemispherical 9 



Tail mamnillate (digitate) 10 



9. L = 0.8 rai,: lip region not. set off by constriction, i. e. 



contimiouG ^X. obtusum Thorne, 1939 



L = 3 r-'-i.j lip region set off by distinct constriction 



X. yaooense n. sp. 



