HYMENOPTERA. 381 



pubescence ; the mandibles obscurely rufo-piceous ; the cheeks 

 with bright silvery pile ; the vertex opake, and having a number 

 of large subimpressed punctures. Thorax : a line of silvery pu- 

 bescence on the posterior margin of the prothorax, another over 

 the tegulac ; the anterior and posterior margins of the scutellum, 

 and the sides of the metathorax covered with silvery pubescence; 

 a silvery line in the middle of the pectus and also on the margins 

 of the mesothorax beneath, very bright and glittering ; a short 

 thin hoary pubescence is scattered over the thorax ; the meso- 

 thorax very smooth and shining, covered with faintly impressed 

 punctures ; the metathorax shining and similarly sculptured to 

 the mesothorax, the truncation transversely striated, and having 

 a deeply impressed longitudinal channel ; wings hyaline, a dark 

 fuscous cloud occupying the marginal cell and passing round the 

 a])ex of the wings. Abdomen smooth and shining, the basal 

 margins of the segments with bands of cinereous pile. 



Hab. St. Domingo. 



19. Trypoxylon clavatum. B.M. 

 Tiypoxylon clavatus. Say, Bost. Journ. i. 374. 2. 



Hab. N. America (United States). 



20. Trypoxylon carinatum. 

 Trypoxylon carinatus. Say, Bost. Journ. i. 3/4. 3. 

 Hab. N. America (Indiana). 



21. Trypoxylon collinum. B.M. 



Female. Length 5^ lines. — Black : the face covered with 

 golden imbescence ; the anterior margin of the clypeus, the 

 sca])e, and five or six of the basal joints of the tiagellum, ferru- 

 ginous. The prothorax, tegulae, legs, and two basal segments of 

 the abdomen, ferruginous ; the wings fuscous, with a violet iri- 

 descence, palest towards their base ; the vertex, mesothorax and 

 scutellum strongly punctured ; the base of the metathorax with 

 divergent striae, beyond which it is transversely coarsely rugose ; 

 in some examples the metathorax has a ferruginous stain at the 

 base. 



Hab. East Florida (St. John's Bluff). (Coll. E. Doubleday, Esq.) 



22. Trypoxylon frigidum. B.M. 



Female. Length 3| lines. — Black : the head subopake ; on 

 the face between the antennae is a slightly elevated carina ; the 

 face and cheeks covered with silvery pubescence. Thorax sub- 



