OF NATURAL HISTORY. 787 



discoidal punctures ; an obvious, compressed tubercle between 

 the antennfe, rounded at its tip : labrum conic : thorax tinged 

 with greenish ;■ with pale yellow hair, except on the middle : 

 wings fuliginous, subopake at tip : tergum tinted with very ob- 

 scure green: basal joint covered with pale yellow hairs : pleura 

 beneath the wing, with yellow hairs. 



Length about four-fifths of an inch. [413] 



% Nasus white. The tubercle of the head is very distinct. 



Common in the Union. The males may be distinguished by 



their larger and more approximate eyes and white nasus. It 



varies in having the hair of the thorax and of the first abdominal 



segment, almost ferruginous. 



2. X. LATERALIS. — Violaccous ; abdomen with a posterior 

 lateral cinereous spot. 



Inhabits Mexico. 



% Body blackish-violaceous : head black : nasus and labrum 

 white : antennae with an anterior white line on the radical joint : 

 gense with a few gray hairs : wings, first recurrent nervure enter- 

 ing the third cellule within the distance of its own breadth froir) 

 the nervure of intersection of the third cellule : abdomen, eacli 

 side near the tip with a cinereous spot of hair, extending up- 

 wards on each side of the venter, but becoming obsolete towards 

 the base. 



Length over seven-tenths of an inch. 



BOMBUS Latr. 



1. B. SONORUS. — Yellow ; head, thoracic band and abdomen 

 behind black. 



Inhabits Mexico. 



Body yellow : head black : thorax with a broad black band in 

 the middle: wings violaceous-black: tergum with the first, 

 second and third segments yellow, the others black : beneath 



black. 



Length 9 four-fifths of an inch. 



Resembles the/ervidm Fabr. so closely that it may readily be 



mistaken for it, but that species has only two segments of the 



tero-um clothed with yellow hair; that of [414] the second on^ 



•however, is so much elongated as to conceal a considerable p<.r. 



1837.] 



