GOMPHUS. 3 



3. Gomphus vulgatissimus. 



Sulys, Monogr. des Gomph., p. 129. 



Plate L, fig. 1, b, c. 



Nympha. male. Length, 31 mm.; breadth, 8 mm. Locality: Europe. 

 Raised by Dr. Brauer, female. Coll. Hagen. 



Head cordate, flat. Eyes large, prominent. Ocelli developed. 

 Oblique groove extending from lateral ocellus to front angle of eye. 

 Vertex square, a little elevated. Part behind the eyes short, notched at 

 middle ; small elevated spots behind eyes. Antennae, two basal joints 

 short, globular, 2d shortest, 3d nearly twice as long as both basal, 

 dilated, somewhat bent up at tip, 4th rudimentary. Mask reaching to 

 the fore legs, quadrangular, channelled in middle, sides bent up, cut 

 straight at fore-border, middle third finely denticulated, and surmounted 

 by comb of bristles. Palpi short, arcuated, finely denticulated at basal 

 half, end hook stout ; movable hooks long and sharp. Prothorax 

 oval, fore-border elevated, a flat impression on each side. Wing-cases 

 reaching nearly to 4th segment. Legs strong, formed for burrowing. 

 Hind legs more widely separated at base. Fore and middle legs 

 short, about equal size. Femora short, stout, bent inward ; tibiaa 

 longer, with strong outer spine at anterior end ; tarsi 2-jointed, short, 

 basal joint very short, claws sharp. Hind legs longer, reaching nearly 

 to 9th segment, flat ; tarsi 3-jointed, 2d, half the length of 3d. Abdo- 

 men long, flat, lanceolate, decreasing in size after 6th segment. Side- 

 border sharp ; segments 2 to 9 with large flat spots. No dorsal hooks. 

 Segments 6 to 9 with lateral spines ; spines of 9th \ as long as 10th 

 segment. Segments of equal length, except 10th, which is small, about 

 \ of foregoing, and cylindrical. Anal appendices a little longer than 

 last segment, pyramidal, sharp. Superior one thickened at basal half; 

 lateral superior ones shorter, sharp. 



Have seen both sexes. Female has abdomen a little broader, and at 

 end of 8 ventral segment a small bifid tubercle, superior appendix not 

 thickened at basal half. 



4. Gomphus species. 

 Plate II., fig. 4, b. 



Nympha, 31 mm.; breadth, 6 mm. 



Locality: Eock Island, Illinois. Coll. Hagen. Mr. Walsh supposed this 

 nympha, judging from perfect insects found in vicinity, to belong either 

 to G. vastus, fluviaiilis, amnicola, or fraternus. 



