NORTH AMERICAN NEUROPTERA. 269 



Group of O. |>la$;iatus (raised). 



Body very elongate; head as broad as abdomen; third joint of antennae twice 

 the length of the two basal, fiat; fourth rudimentary, a smull tubercle; mask ob- 

 long, little longer than broad, little narrower at base, middle third of front border 

 straight (very little rounded in G. olivaceus) ; palpus with a strong end hook and 

 a few sharp teeth just before it; abdomen spindle shaped, four to five times longer 

 than broad, about rounded, segment 9 longer than 8, to twice its length; 10th 

 very short, lateral spines on 6 to 9 ; dorsal hooks none, except a flat, small, trian- 

 gular apical spine on 9 ; apical hook on the four anterior tibife very small : ventral 

 bags on segments 4 to 6. 



G. plagiatus, notafus, spiniceps, olivaceus ? form a type rather differ- 

 ent of all other Gomphus by the long spindle-shaped abdomen, not 

 broader than the head, the length of segment 9 and the rudimentary 

 hooks of the anterior tibiae. G. olivaceus ? is somewhat different, per- 

 haps not belonging here. Of the other species G. vastus is similar, but 

 the hooks of the tibia are very .strongly developed. Probably other 

 species will belong to the group of G. plagiatus. The very abnormal 

 form of the abdomen indicates, perhaps, a higher group than a sub-genus. 



24. Ooniphus plagiatus (raised). 

 Selys Monogr. Gomphin. p. 159. 



Two nympha skins, male and female, from Crescent City, Fla. ; a male 

 nympha in alcohol, the imago, half out, from Dandridge Junction, Tenn. 

 Length 40 mm. 



Body very elongate, little hairy; head cordate, deeply notched behind; eyes 

 large, prominent, hind angles globular, rounded; antennae short, third joint twice 

 the length of the two basal, cylindrical, a little thinner than second, bent up, 

 fourth rudimentary, a rounded knob; mask oblong, one-third longer than broad, 

 channeled below; sides bent up, oblique ; basal third a little narrowed ; middle 

 third of front border nearly straight, with a very short comb of flat scales; palpus 

 short, strong, arcuate, with a strongly bent sharp end hook, and three molars just 

 before it; movable hook long, bent, sharp ; wing cases reaching nearly 4th seg- 

 ment; abdomen five times longer than broad, spindle shaped, as broad as head, 

 very slowly tapering ; rounded above, less below, where the middle part between 

 the longitudinal sutures is broader than the lateral parts; segments of equal 

 length, 9th not fully twice as long as 8, tip half as broad as base, 10th very 

 short, cylindrical, as long as broad ; lateral spines on segments 6 to 9, sharp, long, 

 on 9th half longer than 10th segment; dorsal hooks none, except on 9th a flat, 

 apical, triangular spine as long as segment 10 ; scars as usual; genitals marked; 

 ventral segments 2 to 8 with a round elevation for the ganglia; appendages as 

 long as segment 10, triangular, sharp, laterals very little shorter; legs compara- 

 tively small, the anteriors burrowing legs; hind legs short, reaching end of seg- 

 ment 5 ; third joint of posterior tarsi about as long as the two basal, first joint 

 much shorter than second. 



