1^.2. 



Genus Tylencho la imellus M.V. Cobb, 1915 

 (Key to species modified frcm Thome, 1939) 



1. Neck very short, b = 7 or less 2 



Neck longer, b = S.S or more 3 



2. Combined len-^th of spear and its extensions equal to four times width 



of lip region diplodorus M.V. Cobb, 1915 



Combined length of spear and its extensions twice width of lip region 

 affinis (Rrakenhoff) Theme, 1939 



3. Oral opening surrounded by disc-like structure U 



Oral opening not surrounded by disc-like structure 6 



U. Disc cuticularized, refractive coronatus Thorne, 1939 



Disc not cuticularized 5 



5. Tail subcylindroid, terminus hemispheroid . . . . striatus Thome, 1939 

 Tail convex-conoid to blunt terminus montanus Thorne, 1939 



6. Length 0.9 nim 7 



Length l.b mm sagittifer (de Man) Thome, 1939 



7. Ovary reflexed 1/2 the way back to vulva. . . . magniden s Thome, 1939 

 Ovary reflexed 3/U ^^^ way back to vulva 

 alpinus (Altherr, 1950) Altherr, 1950 



