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



Clypeus squarely truncate; radio-medial cross-vein usually 

 wanting .• 4 



4. Frontal area of head more or less distinct; saw-guides sim- 



ple; elongate species Lygaeonematus p. 115 



Frontal area entirely wanting; saw-guides with a distinct 

 scopa; short, ovate species Pristiphora p. 113 



5. Front wings with free part of Rs always present and the cells 



Rs and R. therefore always separate 6 



Front wings with free part of R5 always wanting and the cells 

 Rb and R4 therefore always united Euura p. 141 



6. Antennae of female filiform, of practically the same width 



throughout; eighth dorsal segment of abdomen of male with 

 a small, blunt, more or less awl-shaped projection; small 



species Pontania p. 137 



Antennae of female setaceous, distinctly tapering toward apex; 

 eighth dorsal segment of abdomen of male with a broad, 

 obtusely pointed projection, or not at all produced at the tip; 

 usually larger than 5 mm 7 



7. Hind tibiae at apex and hind metatarsus not strongly com- 



pressed and flattened 8 



Hind tibiae at apex and hind metatarsus strongly, foliaceously 

 compressed and flattened Crcesus p. 121 



8. Head with frontal area distinct; thorax shining, smooth, at 



most sparsely punctate ; head triangular when viewed in front 9 

 Head with frontal area wanting; thorax opaque, with dense, fine 



punctures ; head round when viewed in front 



Amauronematus p. 121 



9. Male with the last ventral abdominal segment obtusely trian- 



gularly produced at the apex; saw-guides of female of the 



usual form Pteronidea p. 124 



Male with the last ventral abdominal segment excavated at 

 the tip, and not obtusely triangularly produced at the apex; 

 saw-guides of female very broad, large, and thickened .... 



Nematus p. 120 



Diphadnus Hartig. 



Key to Species. 



I. Pronotum with angles broadly yellow 2 



Pronotum with angles black; vertex smooth, shining, frontal 

 crest almost obsolete; third antennal segment longer than 

 fourth; median fovea very minute, circular; saw-guides 

 scarcely projecting, tapering, rather densely clothed with 

 hairs; body shining black, with tegulae and legs light yel- 

 lowish; bases of coxae and anterior femora somewhat in- 



fuscated; antennae pale beneath. Length 5 mm 



appendiculatus 



