^'0.39] ODONATA OF CONNECTICUT: GOMPHIDAE 149 



23. Hind margin of occiput strongly convex, barely emarginate in the 



very middle of the convexity lividus 



Hind margin of the occiput almost straight, or but slightly bisinu- 

 ate so as to form three lobes, the median lobe slightly higher 

 than the two lateral lobes, and not emarginate at its middle .... 



graslinellus 



Group I Brevis-abbreviatus Group 



Gomphus abbreviatus Hagen 



Bulletin de I'Academie royale . . . de Belgique, 46: 464: 1878. 



Nymph. — Measurements, 23-24 mm., length of abdomen, 14 

 mm., width, 6.5 mm., femur, 5 mm. 



Similar in nearly all points to the nymph of brevis, according to 

 Needham. 



Adult, male. — Color yellow and black. 



Head : clypeus, labrum and labium, yellow or pale ; front with 

 a dark stripe on the dorsal surface in front of ocelli ; occiput 

 yellow with a sharp ridge. 



Thorax : pronotum with 2 small mesal spots of yellow and a 

 larger spot on each side; meso- and metathorax black, marked 

 with yellow, the mesepisterna with a rather narrow yellow stripe 

 connecting with the mesothoracic half collar, and a line above the 

 mesopleural suture ; legs black. 



Abdomen: black with yellow on dorso-meson and sides of 

 terga i and 2, 4-7 with yellow spots at base, 8 and 9 with trian- 

 gular spots on sides, the last (8 and 9) segments expanded; supe- 

 rior anal appendages dark brown with a conspicuous tooth beyond 

 middle on the ventral surface (Fig. 21, No. 15) ; dorsal margins 

 of the superiors nearly straight. 



Female. — Color the same as the male. 



Occiput without a distinct ridge as in most Gomphi ; a pros- 

 trate spine present caudad of each lateral ocellus ; vulvar lamina 

 broad, the sides convex, the apical teeth small and median notch 

 shallow (Fig. 20, No. i). 



Measurements : total length, male 42, female 40 mm. ; length 

 of abdomen, male 30, female 28 mm. ; length of hind wings, male 

 23, female 25 mm. ; width of hind wings, male 7, female 8 mm. 



Described from specimens in collections of P. P. Calvert, in 

 Philadelphia Academy of Natural Sciences. 



Gomphus brevis Hagen 

 Bulletin de I'Academie royale . . . de Belgique (2), 46: 460: 1878. 

 Nymph. — Similar in size and shape to nymphs of Ophio- 



gomphus. Labium shown in PI. v. Fig. 10; palpi with fixed hook 



hardly longer than the teeth of the mesal margins. 



Abdomen: of the general type shown in Fig. 17, A, the lateral 



