19. 



Subfamily ACROEHIINAE Thome, 1937 

 (Key to genera after Thorne, 1937) 



1. Labial probolae massive, low, rovinded or furcate plates 2 



Labial probolae slender, furcate or elaborately fringed 5 



2. Cephalic axils dentate, female tails concave- conoid to acute or sub- 

 acute terminus Zeldia Thorne, 1937 P. 19 



Cephalic axils not dentate (except minutely in Chiloplacus 

 trifurcatus ), fanale tails bluntly-rounded, rarely convex- conoid. . 3 



3. Labial probolae, at least the dorsal one, furcate, the submedian ones 



usually asymmetrical Chiloplacus Thome, 1937 P. 20 



Labial probolae low, rounded, not furcate U 



U. Esophagus well developed with enlarged postcorpus, cuticle near head 



with simple annules Acrobeloides Cobb, 192U P. 21 



Esophagus slender throughout, cuticle near head divided into plates 



Placodira Thome, 1937 



(Contains a single species P. lobata Thome, 1937) 



5. Labial probolae elaborately fringed . . . .Acrobeles von Linstow, 1877 P. 22 

 Labial probolae slender, furcate, rarely with a few branches v ... 6 



6. Cuticle with transverse striae only Cervidellus Thorne, 1937 P. 23 



Cuticle with both longitudinal and transverse striae 



Stegelleta Thome, 1938 P. 23 



Genus Zeldia Thorne, 1937 

 (Key to the species after Allen, 195o) 



1. Labial probolae low and rovmded 



punctulata (Thome, 1925) Thome, 1937 



Labial probolae plate-like, bifurcate 2 



2. Annules marked by h lines of punctate dots 



punctata (Thome, 1925) Thorne, 1937 



Annules not marked by pimctate dots 3 



3. Excretory pore far in front of nerve ring 



glaphyra (Steiner, 1935) Thorne, 1937 



Excretory pore located near the nerve ring 

 setosa (Cobb, 191U) Thome, 1937 



(Description derived from an immature specimen) 



