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 R 5 always wanting and the cells 

 R 5 and R* 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 



Antenna? 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 



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. 



1. 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 teguhe and legs light yel- 

 lowish; bases of coxae and anterior femora somewhat in- 



fuscated; antennae pale beneath. Length 5 mm 



appendiculatus 



