OF NATURAL HISTORY. 7H7 



discoidal punctures; an obvioun, compressed taJxTcl.' h.-twecn 

 the antennae, rounded at its tip: labrum conic: thorax tinjjod 

 with <,'reonish ; with palo ydlcw hair, except on the middle : 

 wings fuliginous, subopake at tip : tergura tinted with ve^y ob- 

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

 beneath the wing, with yellow hairs. 



Length about lbur-{ifth.>< of an inch. [4131 



% Nasus white. The tubercle of the head i.s very distinct. 



Common in the Union. The males may be distingui.shed by 



their larger and more approxin»ate eyes and white nai»u». It 



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



segment, almost ferruginous. 



2. X. LATERALIS. — Violaceous; abdomen with a po^trrim 

 lateral cinereous spot. 



Inhabits Mexico. 



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

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

 genae with a few gray hairs : wings, first recurrent nervure ent«r- 

 ing the third cellule within the distance of its own breadth from 

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

 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. 



BOM BUS 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-blnck : t-ergum with the fin«f, 

 second and third segments yellow, the others black : beneath 

 black. 



Length 9 four-fifths of an inch. 



Resembles the /miilus Fabr. so closely that it may readily br 

 mistaken for it, but that species has only two s«>gment« of the 

 tergum clothed with yellow hair; that of [414] the second one, 

 however, is so much elotigated iu? to conceal a con.sidcrablc por- 

 1837.] 



