AMERICAN HYMENOPTERA. 321 



B. Posterior wings without nervures, except the costal and a trace of the anal. 

 Hind coxae of the females greatly prolonged within. Tarsal claws 

 with no teeth Paiiiniegiscliia Provancher. 



DEKAIDONTUS nov. gen. 



Head subquadrate, antennse inserted just above the clypeus; pro- 

 thorax with an acute tooth on the somewhat angled margin ; meso- 

 thorax with the medial lobe often gibbous, always rugose ; wings 

 often with more or less fuscous on the basal half, as well as below 

 the stigma; the ungula bear four well-defined teeth beneath; abdo- 

 men clavate ; ovipositor strongly exerted. 



Type (Aulacus) montanus Cresson. 



Medial mesothoracic lobe strongly gibbons. 



Wings hyaline, without violaceous reflection ; abdomen black, except the ven- 

 tral part of the first segment, which is sometimes dull rufous 



iiiger Shuckard. 

 Wings of the 9 showing strong violaceous reflection ; abdomen rufous, marked 



with black iiiont/aiiuis Cresson. 



Medial mesothoracic lobe not gibbous. 



Wings showing strong violaceous reflection ; much fuscous present in the basal 



portion ; legs black ; petiole short fuscalatns nov. spec. 



Wings without violaceous reflection, or more than a trace of fuscous in the 

 basal portion ; legs flavous ; petiole long. . . -flavicriirus uov. spec. 



Deraiodoutus uiger Shuckard. 

 1841. Aulacus niger 9 Shuckard, Entomologist, p. 124. 



1841. Atdacus ater 9 Westwood, Ann. and Magazine Nat. Hist., vii, p. 538. 

 1901. Pristaulacus niger Ashmead, Ent. News, xii, p. 278. 



9 %. — Black; sparingly pubescent; face finely punctulate, pubescent; verte:f 

 more sparingly punctulate; antennte black, 12 mm. long; medial mesothoracic 

 lobe gibbous, emarginate, rugose; wings hyaline, with a very faint trace of fus- 

 cous beneath the stigma and in the median cell ; legs black, tending to castane- 

 ous; abdomen entirely black, or more usually with a deep red band on the ven- 

 tral part of the first segment; ovipositor 17 mm. long. Length 14 mm. 



Habitat — Massachusetts. 



Deraiodouf lis iiiontaniis Cresson. 

 1879. Aulacus montanus Cresson, 9- Trans. Am. Ent. Soc, vii, p. 256. 

 1901. Pristaulacus montanus Ashmead, Ent. News, xii, p. 278. 



9. — Black; sparingly pubescent; face and vertex smooth; face pubescent; 

 antennse black. 10 mm. long; mesothorax with the medial lobe gibbous and 

 emarginate, rugose; wings hyaline or slightly yellow, showing strong violaceous 

 reflection ; a quadrate fuscous spot beneath the stigma ; a trace of fuscous often in 

 the median cell and along the transverse medial nervure; legs black: abdomen 

 ferruginous, posterior segments and petiole black ; ovipositor 13-14 mm. long. 

 Length 11-14 mm. 



TRANS. AM. ENT. SOC, XXVII. (41) NOV., 190]. 



