528 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



in olscuras} Fourth segment of antenna nearly one-half as long as 

 thhd (in ohscurus one-third to one-fifth.) Abdomen with lateral 



Figs. 155-163.-Peogomphus borealis, nymph. 157. First leg. 158. Mentum, detail. 159. Head. 

 160. Mentum. 161. Segments 9 and 10 of male. 162-16,3. Segments 9 and lo of female. 



spines on segments 3-9 (in ohscurus on 5-9) ; dorsal spmes on seg- 

 ments 1-9, those o n segments 1-3 large and recurved, the remainder 



1 Needham and Hart., Bull. III. State Lab. Nat. Hist., vol. 6, art. l, 1901, p. 94, pi. l, fig. 3. 



