118 HYMENOPTERA OF AMERICA. [ TAUT I. 



anteriorly; the prothorax with a crested margin, its angles 

 dentiform, acute. Post-scutel very short, strongly truncate; its 

 posterior face flat, polished; its superior face rough, transverse; 

 its posterior ridge wvy finely crenulate, the middle with a very 

 small compressed tubercle. Metathorax coarsely cribrose, silky- 

 grayish, its hinder fare widely excavated, as polished as the 

 posterior face of post-scutel, somewhat punctate, finely margined; 

 the margins forming behind the post-scutel two quite small erect 

 teeth (not easy to distinguish); no distinct lateral angles. 

 Abdomen slender, slightly depressed; the first segment small, 

 shortly and quite sharply truncate anteriorly; the suture elevated; 

 its superior face short, rather strongly punctured; 2d segment 

 not quite so strongly punctured, its hinder margin with a line of 

 puncture.-, the following segments densely punctured. 



Black; grayish-silky. Mandibles partly fulvous; antenna? 

 ferruginous beneath, scape yellow beneath. Two dots on the 

 summit of clypeus, a frontal spot, and post-ocular line, pale yel- 

 low. Hinder margin of prothorax with a narrow lutcous band; 

 its angles, appendix of wing scale, a spot under the wing, an 

 interrupted fascia on scutel, a transverse line on the hinder face 

 of post-scutel, and two large maculae on the hind face of meta- 

 thorax, pale yellow. The first two abdominal segments narrowly 

 margined with lutcous. Intermediate femora with a lutcous line. 

 Anterior tibiae and tarsi brown or ferruginous. Wings hyaline, 

 smoky, nerves and anterior margin of the apex fuscous; the 2d 

 recurrent nerve falling nearly upon the 2d transverse cubital vein. 



Var. Anterior margin of prothorax also margined with luteous. 



Bess. a. diff. — This is quite a distinct species and a peculiar 

 type, making a sort of transition to Stenodynerus by its slender 

 form, and its punctate abdomen, having the 1st segment more 

 punctured than the second. The form of the scutel, post-scutel, 

 and metathorax is quite unusual, and the very coarsely punctured 

 thorax makes it at once distinguishable. 



Its livery much resembles that of the A. Fnria<n\ but it differs 

 from this in all its form and its punctures; in the first segment 

 being very short and truncate, its superior face quite transverse; 

 the scutel truncate, not triangular; the punctures of thorax and 

 head being miteli roarsor, etc. It has also a resemblance to 0. 

 (Slenodynerut) (otonacus. 



