50, 



llt» Lip rc:;^;ion continuous x-ath body contour «.«.»........ .11; 



lip re^jion set off by constriction or depression, . . . , . » . . . 22 



iSm Lip rejion bearin;j 2 annules nudus Allen, 1955 



Lip bearinij more th.-m 2 annules l6 



16. Lip sclerotization f nint, inconspicuous 17 



Lip sclerotization strong, conspicuous, 20 



17. Tail bearin;^ 10 to l5 annules ,- 18 



Tail bearing 20 to 27 annules . , 19 



18. Lip region bearing 5 annules; spear 15-17 as long. . clarus Allen, 1955 



Lip region bearing 3 annules; spear 18-20 as long 



eniTin^i Hopper, 1959 



19. Lip region bearing 5 annules; tail subcylindrical . striatus A3.1en,1955 



Lip region bearing 3 annules; tail snriiewhat clavate ....' 



.« martini Fielding, 1956 



20. Spear less than 20 u long . manubriatus Litvinova, 19ii6 



Speai' more than 20 u long 21 



21. Spear not more than 31 u long, tail bearing 50 annules 



• • kegenicu s Litvinova, 19li6 



Spear more than 31 u long, tail bearini^ i;5 annules , 



galeatus Litvinova, 19ii6 



22. Spear more than 20ulong, lips rounded, sclerotization conspicuous • • 



••.... cylindricus Cobb, 1913 



Spear less than 20ulong, lips broadly rounded, sclerotization faint. 23 



23. Lip region bearing 6 annules; tail conoid, bearing approximately l6 



annuals latus Allen, 1955 



Lip region bearing 3 annules; tail somewhat clavate, bearing approxi- 

 mately 26 annules martini Fielding, 1956 



2h. Tail about 2 X anal body diameter, beai-ing less than 25 annules . . • 



acutus Allen, 1955 



Tail about 3 X anal body diarrteter bearing more than 25 annules. . . .25 



25. Tail bearing about 32 annules, terminal annule not enlarged 



capitatus Allen, 1955 



Tail bearing about lj2 annules, terminal annule enlarged 



..,» , acti Hopper, 1959 



26, Annules extending around terminus of tail 27 



Annules not extending around terminus of tail 31 



27. lip region set off by constriction or depression. . Iqjtus Allen, 1955 

 Lip region not set off by constriction or depression 28 



28, Lip sclerotization well developed, conspicuous, . macrmnis Allen, 1955 

 Lip sclerotization faint, inconspicuous 29 



