220 BULLETIN 66, UNITED STATES NATIONAL MUSEUM. 



Plate 4. 



Family Stylopidve (females). 



Page. 



Fig. 1. Stylops nasoni, cephalothorax 104 



2. Stylops nubeculse, cephalothorax 105 



3. Stylops oklahomse, cephalothorax 110 



4. Stylops polemonii, cephalothorax, full of triungulinids 106 



5. Stylops salicifloris, cephalothorax 106 



6. Stylops solidulse, cephalothorax 107 



7. Stylops sparsipilosse , cephalothorax 108 



8. Stylops subcandidae, cephalothorax, containing triungulinids 108 



9. Stylops swenki, cephalothorax, containing triungulinids 108 



10. Stylops vicinx, cephalothorax 110 



11. Stylops vierecki, cephalothorax 110 



Illustrations from photomicrographs taken by H. S. Barber and E. S. 



Tucker, and retouched by the author. 



Plate 5. 

 Family Hylechthrid^; (males). 



Fig. 1. Hylechthrus rubi, wing (after Saunders) 114 



2. Hylechthrus rubi, mouth parts, front view (after Saunders) 114 



Family Xenid^e (males). 



3. Xenos jurinei, mouth parts, front view (after Jurine) 118 



4. Xenos vesparum, wing (after Saunders) 117 



5. Schistosiphon peckii, thorax, abdomen and wing (after Kirby) 133 



6. Schistosiphon peckii, genitalia (after Kirby) 133 



7. Acroschismus bruesi, genitalia (lateral view) 124 



8. Acroschismus wheeleri, oedeagus 129 



9. Acroschismus wheeleri, wing 129 



10. Acroschismus bruesi, wing 124 



11. Acroschismus bruesi, mouth parts 124 



12. Acroschismus wheeleri, mandible 129 



13. Acroschismus wheeleri, maxilla 129 



Drawings by the author. 



Plate 0. 



Family Xenid^e (males). 



Fig. 1 . Acroschismus hubbardi, face 122 



2. Acroschismus hubbardi, antenna 122 



3. Acroschismus hubbardi, elytron, from above 122 



4. Acroschismus hubbardi, stigmatal lobe, from below 122 



5. Acroschismus hubbardi, prosternum 122 



6. Acroschismus hubbardi, meso- and metasternum 122 



7. Acroschismus hubbardi, head and thorax, dorsal. 122 



8. Acroschismus hubbardi, abdomen, lateral 122 



9. Acroschismus hubbardi, oedeagus 122 



10. Acroschismus hubbardi, genitalia, lateral view 122 



11. Acroschismus hubbardi, wing 122 



12. Acroschismus hubbardi, nodal portion of wing 122 



Drawings by the author. 



