226 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.53. 



2. Face heavily lined witli black; superior appendages about same length as 



inferior appendage brevis. 



Face not lined with black; superior appendages plainly longer than inferior 

 appendage 3 



3. Rear of head black, except for one or more small spots near margin of eye; 



inferior appendage in lateral aspect strongly narrowing in apical half; 

 genital vesicle in lateral aspect long, slender, its apical half directed 



slightly backward viridifrons. 



Hear of head pale on lower half, black on upper half; inferior appendage in 

 lateral aspect not strongly narrowing in apical half; genital vesicle in 

 lateral aspect short, stout, erect ahbreviatus. 



The following material has been studied: The single male of the 

 nev^ species Gomphus farvidens^ described herein; 34 males and 34 

 females of G. hrevis and 7 males and 4 females of G. ahbreviatus^ 

 collected at Orono, INIaine, during June and July of 1898 and 1899 

 by F. L. Harvey and Bartle Harvey (Coll. U.S.N.M.) ; and a male 

 of G. viridifrons^ collected at Ohio Pyle, Pennsylvania, June 25, 

 1900, by E. B. Williamson (Coll. E. B. Williamson). 



The specimens from which the drawings were made are so labeled 

 and, with the exception of Gomphus viridifrons^ are in the collection 

 of the United States National Museum. 



EXPLANATION OF PLATES. 



Plate 27. 



Figure 1 is from a photograph by Mr. H. J. Paine, of the Bureau of En- 

 tomologj'. The outlines in figures 2 and 3 are adapted by the writer from one 

 used by Mr. E. B. Williamson in illustrating markings in the genus Cyano- 

 gomphus. 



Fig. 1. — Gomphus parvidcns. Male, dorsal view, X 2. 



2. — Gomphus parvidcns. Diagram showing pattern of thoracic markings. 

 3. — Gomphus brevis. Diagram showing pattern of thoracic markings. 



Plate 28. 



Figs. 1-3 and 7. Gomphus parvidcns. 1. Terminal abdominal appendages of 

 male, dorsal aspect. 2. Same, ventral aspect. 3. Same, 

 lateral aspect. 7. Accessory male genitalia of second ab- 

 dominal segment, lateral aspect. 

 4andS. Gomphus abbrcviatus. 4. Terminal abdominal appendages of 

 male, lateral aspect. 8. Accessory male genitalia of second 

 abdominal segment, lateral aspect. 



5 and 9. Gomphus viridifrons. 5, Terminal abdominal appendages of 



male, lateral aspect. 9. Accessory male genitalia of second 

 abdominal segment, lateral aspect. 



6 and 10. Gomphus brevis. 6. Terminal abdominal appendages of male, 



lateral aspect. 10. Accessory male genitalia of second ab- 

 dominal segment, lateral aspect. 



Drawings for all figures executed by Miss Esther Hart, 

 of the Bureau of Entomology. 



