204 MODERN CLASSIFICATION OF INSECTS. 
the anterior tibiz and tarsi being strongly ciliated, and the posterior 
tibize spined in the females. 
Some of these insects, inhabiting tropical climates, are amongst the 
largest of Hymenopterous insects, the wings measuring not less than 
four inches in expanse. They are exceedingly active and very restless 
in their motions, and may often be seen upon sand-banks, &c. running 
along with their wings in constant vibration. ‘Their sting is very 
powerful. They are considerably varied in their colours, and a few 
of them are splendidly metallic. 
Latreille in some of his earlier works divided this family into two, 
the Sphegides and Pompilides. In his Genera Crustaceorum, however, 
as well as in the second edition of the Régne Animal, they consti- 
tuted but a single family. I therefore regard them as subfamilies. 

The first subfamily Sphegides has the collar narrowed in front, 
forming an elevated piece or node ; the first segment of the abdomen, 
as well as occasionally a part of the second, is contracted into an 
elongated peduncle; the fore wings always exhibit three perfect 
submarginal cells, and the commencement of a fourth terminal one. 
Of these insects, Ammophila A7zrby, and Pelopzeus Fad. are both re- 
markably distinguished by the extreme slenderness and length of the 
abdominal peduncle, which, especially in the latter, is not thicker than 
a fine pin. The genus Ammophila (fig. 83.1. A. sabulosa ? ; fig. 2—183. 
details of this species), as the generic name imports, was established 
by Mr. Kirby in an interesting memoir published in Linn. Soc. Trans. 
vol. iv. and is further distinguished by the great elongation of the 
maxilla and labrum (fig. $3.2. represents the front of the head; 
Jig. 83. 8. the labrum; fig. 83. 4. the mandible ; jig. 83. 5. the max- 
illa with its apical lobe reflexed; jig. 83. 6. the same with the lobe 
extended; fig. 83. 7. the labium, with the ligula partially withdrawn 
