AMERICAN DIPTERA. 231 



EXPLANATION OF THE PLATES. 



Explanation of the Lettering. 



The letters a, b, c, etc., are repeated on different figures to refer 

 to miscellaneous structures that have no definite names and which 

 are described in the text. The other symbols used are abbreviations, 

 and are explained in the following : — cm., anus ; ap., apodeme ; ap. 

 ap., apical appendage ; ap. aps., apical appendages ; a. t., anal tube ; 

 b7\, V-shaped brace between the posterior arms of the central vesi- 

 cle ; c. v., central vesicle; ej. d., ejaculatory duct; y. c, genital 

 chamber ; gon. 2, second gonapophyses ; p., penis ; p. g., guard of 

 penis; pL, pleurum ; r., rectum; s., sternum; t., tergum ; A, first 

 apical appendage ; B, second apical appendage ; C, third apical 

 appendage; H, hypopygium ; VII, VIII, IX, seventh, eighth and 

 ninth abdominal segments. 



Explanation of the Figures. 



PLATE VIII. 

 Fig. 1. Dicranomyia venusta, lateral view of terminal part of abdomen. 

 " 2. " longipennis, guard of penis (p. g.) and second gonapophyses 



(gon. 2), left view. 

 " 3. Antocha sp. ?, penis, dorsal view. 



" 4. Dicranomyia longipennis, terminal part of abdomen, dorsal view. 

 " 5. Antocha opalizans, terminal half of abdomen, lateral view, x 25. 

 " 6. Antocha sp. ?, guard of penis, dorsal view. 

 " 7. " sp. ?, second gonapophyses of left side, lateral view. 



" 8. " opalizans, guard of penis, dorsal view. 



" 9. Trimicra anomalu, terminal part of abdomen, dorsal view. 

 " 10. Symplecta punctipennis, second gonapophyses and their apodemes {ap.), 



dorsal view. 

 " 11. Antocha opalizans, second gonapophyses of left side, lateral view. 

 " 12. Symplecta punctipennis, terminal part of abdomen, dorsal view. 



TRANS. AM. ENT. SOC. XXX. JULY. 1904. 



