186 THE CANADIAN ENTOMOLOGIST. 



Male superior appendages yellowish-brown, much longer than lo, divaricate at 

 almost a right angle, slightly incurved toward the tip and cut obliquely to form an obtuse 

 external angle at two - thirds their length, and a supero-internal point. The 

 bevelled portion is minutely denticulate opposite the apices of the inferior appendage. 

 No teeth or spines. The inferior appendage is bifid half its length with branches 

 strongly divergent and strongly upcurved, their apices resting outside the bevelled 

 portion of the superiors. Posterior genital hamule simple; pointed, directed forward at 

 an angle of 45 degrees with the axis of the abdomen. 



Name refers to its extremely local occurrence. 



The single imago was obtained by Mr. C. A. Hart and myself, by 

 rearing a nymph which we found crawling from the water upon bur-rush 

 leaves, 23rd June, 1896, in the mouth of Quiver Creek. I obtained 

 several exuvise there^ and several others later at McHairy's mill-dam 

 some miles further up. 



The nymphs of this and of the preceding species will be described 

 in a forthcoming bulletin of the Illinois State Laboratory of Natural 

 History. 



Since this paper was written, T have obtained at Ithaca, N. Y., 

 nymphs which can be none other than Dromogomphus spinosus, Selys. 

 They fall in the same section of the table with Arigotfiphtis, Stylurus and 

 Gomphus, from all which they are distinguished by a sharp middorsal 

 longitudinal ridge, ending in a straight apical spine on the 9th abdominal 



segment. 



Explanation of Plate 7. 



Figs. I, 2, 3 and 4. — The occiput of the female of Ophiogomphus 

 carolus, seen from the front, showing variations in occipital spines. 



Fig. 5. — Genital hamules of Ophiogomphus johatmus from the left 

 side, inverted. 



Fig 6. — Do. of Ophiogomphus carolus. 



Fig. 7. — -Inferior abdominal appendage of 0. carolus seen from 

 below. 



Fig. 8. — Head of nymph of Lanthus parvulus, seen from above and 

 in front. 



Fig. o — -Mentum of labium of do. from above. 



Fig. 10 — End of abdomen of do. 



Fig. II. — End of abdomen oi Gomphus fratertius, nymph. 



Fig. 12 



Fig. 13 



Fig. 14 



Fig- 15 



Fig. 16 



-Part of labium of do. 



•End of abdomen of Arigomphus pallidus, nymph. 



-Part of labium of do. 



-End of abdomen of Stylurus segregans, nymph. 



-Part of labium of do. 



