1893.] NATURAL SCIENCES OF PHILADELPHIA. 471 



ing to the tegulre ; nietathorax shorter than the dorsulura; marginal 

 cell long, lanceolate, without appendiculation; two or three cubital 

 cells, when there are three the second ispetiolated; point of reception 

 of the recurrent nervures by the cubital vein variable; the cubital 

 vein of the hind wings, originates beyond the apex of the submedian 

 cell ; armature of the legs very feeble ; middle tibia? with one spur; 

 outer side of anterior tibiae with or without insignificant spines; 

 second abdominal segment above generally with a transverse de- 

 pression at base ; last dorsal segment of the female conical, without 

 pygidial area, in the male shorter. 



But one species of Pison has been described from Boreal America, 

 and that I have not succeeded in identifying. 



P. laeve Sm. 

 P. laez'is Sm., Cat, Hym. Brit. Mus. IV, 1856, p. 317. 9 . 

 P. laeve Kohl, 1. c. p. 187. 



"$ . — Length 3-i lines (7 mm.) Head opaque, the face covered 

 with silvery pubescence ; the metathorax smooth and shining with a 

 few scattered punctures at the sides, the central chaunel without a 

 carina; a deep elongate-ovate fossula in the middle of the truncation, 

 the margins of the latter rounded ; the wings slightly fuscous, the 

 nervures black ; the two recurrent nervures uniting with the nerv- 

 ures of the petiolated submarginal cell. Abdomen smooth and shin- 

 ing, very delicately punctured, the margins of the segments slightly 



depressed. ' ' 

 Georgia. 



TRYPOXYLON Latr. 

 Trypoxylon Latr., Prec. car. gen. Ins. 1796; Kohl. 1. c. p, 190. 



Head as broad or a little broader than the thorax, formed as in 

 Pison ; mandibles without emargiuation on outer edge ; inner mar- 

 gin of the eyes strongly emarginate ; ocelli normal, distinct; antenna? 

 tolerably long, usually clavate, generally more strongly so in the 

 male, last joint almost always elongated, in the female small, in the 

 male strong and exceeds the length in very many cases the third anten- 

 nal joint ; in the hind wings the cubital vein originates on the medial 

 vein beyond the apex of the submedian cell ; armature of the legs very 

 poor ; middle tibia? one spurred ; claws entire ; anterior tarsi without 

 a comb; radial cell of fore wings long, lanceolate, without appendicu- 

 lation ; only one cubital and one discoidal cell ; abdomen elongated, 

 clavate ; last segment without pygidial area ; in the female conical, 

 in the male truncate. Size variable. 



