REVISION OF THE TRIBE PAEDERINI — ^BLACKWELDER 97 



13. Pronotum sculptured similarly to head; prosternum trans- 



versely impressed before coxae; fifth sternite not lobed Pycnocrypta 



Pronotum scarcely distinguishably sculptured; prosternum not 

 transversely impressed before coxae; fifth sternite of male 

 lobed behind at middle Biocrypta 



14. Fourth segment of maxillary palpus not strongly compressed or 



very short, glabrous 15 



Fourth segment of maxillary palpus compressed, truncate, and 

 pubescent Paederus 



A. Elytra closely appressed to metathorax and abdomen, narrowed at base with 



basal angles more or less obliterated; hind wings absent B 



Elytra normal, quadrate, not closely appressed, generally larger than base of 

 abdomen and not strongly narrowed, with basal angles rounded but dis- 

 tinct; hind wings present subgenus Paederas 



B. Each mandible with an additional dorsal tooth subgenus Gnathopaederas 



Mandibles without additional dorsal teeth . subgenus Neopaederus « 



15. First segment of antennae large, rest smaller, even, strongly com- 



pressed from sixth, with dense pile and long setae at sides of 



each segment from sixth Suniotrichus 



Antennae normal or with first two segments larger and rest not 



compressed 16 



16. Neck never at all less than one-fourth as wide as head; apex of 



posterior tibia with a distinct ctenidium on both sides 17 



Neck variable; apex of posterior tibia with a ctenidium only on 



inner side 25 



17. Eyes wholly obsolete Qlyptoraerus 



Faceted eyes present and distinct 18 



18. Fourth segment of maxillary palpus large, conical, apex trun- 



cate 19 



Fourth segment of maxillary palpus small, acute or acicular 20 



19. Labrum completely divided into 2 elongate lobes Achenium 



Labrum divided into 2 transverse rounded lobes Scimbalium 



20. Fourth segment of maxillary palpus longer than greatest width 



of third; labrum semicircularly emarginate; punctation dense 



and umbilicate Scopobium^ 



Fourth segment of maxillary palpus shorter than greatest width 

 of third; labrum bilobed or triangularly emarginate; puncta- 

 tion generally not umbilicate __ 21 



21. Head with punctures not very dense, not coarsely umbilicate 22 



Head with very dense umbilicate punctures Domene 



A. Elytra with pleural fold „ subgenus Domene 



Elytra without pleural fold subgenus Neodomeno • 



• Neopaedema, new subgenus. Diagnosis: Characters of genus Paederus except as follows: Mandibles 

 without an additional dorsal tooth; elytra closely appressed to thorax, narrowed at base with the basal 

 angles more or less obliterated; hind wings absent; anterior tarsi strongly dilated. 



• Scopobinm. new genus. Diagnosis: Punctures dense and umbilicate; antennae normal; labrum broadly 

 semicircularly emarginate; fourth segment of maxillary palpus acicular, longer than the greatest width of 

 the third; gular sutures very approximate throughout their length, not at all united though obscured by 

 the sculpture; neck about one-half as wide as head; prosternum not dilated beneath the coxae; hypomera 

 prolonged in a lobe partly behind the coxae; anterior coxal cavities entirely open behind; front coxae very 

 large, exserted; middle coxal cavities confluent; posterior coxae contiguous, "conical"; first and second 

 abdominal stemltes absent, third strongly carinate at middle basally; basal half of front tibia with a con- 

 cavity lined with diagonal ctenidia; front tarsi broadly expanded; apex of posterior tibia with a ctenidium 

 on each side. 



• Neodomene, new subgenus. Diagnosis: Characters of genus Domene but lacking any trace of a pleural 

 fold above the side margin of the elytra. 



