AMERICAN ENTOMOLOGY. d 



Ben/ibex, in the general appearance of the insects of which it is 

 composed, as well as in the distribution of the nervures of their 

 wings. This affinity is so striking in many species of these 

 groups, that it becomes necessary to inspect the form of the la- 

 brum, in order to decide upon their respective appropriate genus. 

 A very remarkable difference is observable in this organ, which 

 in those genera, is much elongated and triangular, but in Stizus, 

 it is short and semiorbicular. Nearly all the species have three 

 spines at the extremity of the abdomen, as in the genus Scolia, 

 but they cannot be considered as Scolise, as their eyes are entire, 

 and the form and number of the wing cellules are altogether dif- 

 ferent. 



Stizus grandis. — S})ecific character. Segments of the ab- 

 domen, each with a yellow band, and lateral blackish spot. 



Stizus grandis nobis, Western Quarterly Reporter, vol. ii. 

 p. 77. 



Desc. Antennas black, the three basal joints rufous ; front and 

 labrum yellowish ; thorax with a yellowish spot on the anterior 

 angle, and first segment margined with yellowish ■ scutel ferrugi- 

 nous ; wings ferruginous, dusky at tip ; feet ferruginous ; tergum 

 ferruginous, each segment with a yellow band, and lateral, black- 

 ish, oblique, sublinear spot ; venter with an obsolete margin on 

 the second segment, and obsolete lateral triangles on the remain- 

 ing segments, yellowish. 



Male. Head, thorax, base of the three or four terminal, and of 

 the abdominal segments, and beneath, black ; bands of the abdo- 

 men uninterrupted ; lateral spot of the first band obsolete or 

 wanting ; anal spines none. Length to the tip of the wings, one 

 inch and a fifth. 



Female. Ferruginous ; basal band of the abdomen, and some- 

 times the second and third bands, interrupted in the middle ; 

 lateral spot of the first abdominal band very oblique. Length to 

 the tip of the wings, one inch and three fifths. 



Obs. This remarkably fine and new species is very distinct from 

 the speciosus of Drury, and is somewhat larger than that com- 

 mon insect. When descending along the bank of the Arkansa 

 river, with a detachment of Major Long's exploring party, 1 had 

 frequent opportunities of observing this species. It generally 

 occurred upon flowers, in company with many other interesting 

 Ilymrnopterous insects. It is highly probable, that, like the 



