HYMENOPTERA. 436 



M. Wesmael has proposed the removal of this species from the 

 genus Psen, in consequence of a difference in the neuration of 

 the posterior wings. Throughout this catalogue the determina- 

 tion of the genera has been estabUshed on the neuration of the 

 anterior wings in connexion with other characters. 



2. Psen pallipes. B.M. 



Sphex paUipes, Panz. Faun. Germ. 52. 22 S • 

 Trypoxylon atratum, Panz. Faun. Germ. 98. 15. 

 Psen atra, Panz. Krit. Revis. ii. 109. 

 Psen atratus. Van d. Lind, Obs. ii. 103. 2. 



Shuck. Foss. Hym. 227. 2. 



Dahlb. Hym. Europ. i. 5. 6. 



St.Farg. Hym. iii. 40. 1. 



Wesm. Hym. Foss. Belg. 116. 1. 



Hah. Britain; France; Germany; Belgium; Sweden; Finland. 



3. Psen fuscipennis. 



Psen fuscipennis, Dahlb. Hym. Europ. i. 5. 7 ? • 

 Hub. Scandinavia. 



4. Psen medius. B.M. 



Male. Length 3 lines. — Head black, closely punctured ; 

 the face covered with silvery pubescence ; the mandibles and 

 flagellum beneath rufo-fulvous. Thorax black, strongly punc- 

 tured, the punctures confluent in the middle of the disk; the 

 metathorax very coarsely rugose; the sides and beneath the 

 thorax with a short glittering pubescence ; the tubercles, tegulae, 

 extreme base of the wings, anterior and intermediate legs, and 

 the posterior tibiae and tarsi, rufo-fulvous; the intermediate 

 femora with a dark stain beneath ; the wings hyaline and beauti- 

 fully iridescent. Abdomen black, with the apical margin of the 

 first segment and the second entirely red; the petiole wider at 

 its extremity than at its base ; the apical margins of the third 

 and following segments rufo-piceous ; the entire abdomen has a 

 thin silky pile ; beneath, coloured the same as above. 



Hub. Brazil (Santarem). (Coll. II. W. Bates.) 



This insect has exactly the appearance of M. bicolor, but it 

 differs considerably from it in sculpture, and the neuration of its 

 wings is that of Psen : it appears to form a connecting link be- 

 tween the two genera. 



