l68 CONNECTICUT GEOL. AND NAT. HIST. SURVEY [Bull. 



Dromogomphus spinosus Selys 



Bulletin de rAcademie royale . . . de Belgique, 21 : 59 : 1854. 



Nymph (PI. iii, Fig. 6). — Head: labium extending caudad 

 between the front coxae ; distal margin of the median lobe slightly 

 concave (PI. v, Fig. 9), the labial palpi with 6 to 7 teeth on the 

 mesal margins ; antennae with the third segment cylindrical or 

 only slightly flattened, the fourth minute, almost indistinguishable. 



Thorax : wing-cases reaching the fourth abdominal segment, 

 the hind femora reaching about to the middle of that segment. 



Abdomen: a sharp distinct ridge on the dorsum of segment 9, 

 sharp projecting dorsal hooks on segment 6-9 inclusive and tuber- 

 cular dorsal prominences on segments 2-5, lateral spines on seg- 

 ments 6-9 inclusive, that on 9 about half the length of segment 10. 



Measurements: total length (exuviae), 32-33 mm.; length of 

 abdomen, 22 mm. ; length of hind femora, 5-6 mm. ; dimensions 

 of segment 9, 2.8-3 n^f"- long by 4 mm. wide at base. 



Adult, male. — Color dark brown and yellow. 



Head : labium and face below the antennae yellow, dark imme- 

 diately in front of the antennae ; ocellar area dark ; curved ridge 

 behind the ocelli, without a conspicuous spine at each end ; occip- 

 ital ridge depressed at center, the ridge with long black setae; 

 occiput black ; postgenae black above, pale below. 



Thorax : pronotum black with cephalic and caudal margins yel- 

 low, and a yellow spot on the meson in contact with the caudal 

 division ; dorsal carina and mesothoracic half-collar yellow, dorsal 

 stripes of the mesepisterna not connected with the collar and rather 

 closely approximated to the carina, also slightly diverging cephalad ; 

 a faint line above the mesopleural suture ; ventral half of the meso- 

 katepisterna yellow ; metapleura and venter of the thorax yellow. 

 Ventro-caudal surface of the front femora yellow, remaining 

 femora and all tibiae and tarsi black ; hind femora with five to six 

 long spines, in one row beneath, and another row of spines approx- 

 imately one-third this length also on the venter. 



Abdomen: black or dark brown and yellow, the dorsal longi- 

 tudinal stripe extending from terga i to 8 inclusive, trilobed on 

 tergum 2 ; broad lateral stripes on terga i to 3 or 4, very distinct, 

 more or less confused with brown on 5 to 9 ; terga 10 dark brown, 

 obscurely pale above ; superior anal appendages entire, not toothed, 

 the inferior about as long as the superiors, broadly bifurcate, the 

 arms upcurved at tips. 



Female. — Color as in the male though usually brighter. 



Head : ocellar ridge with a sharp spine at either end ; occiput 

 3'ellow. 



Abdomen: vulvar lamina acute at tips, the lateral margins 

 plainly concave, median notch apparently extending to the bases 

 of the plates, the plates in contact for half this length. 



Measurements : total length, male 55, female 57 mm. ; length 



