168 HYMENOPTERA. 
there exists a remarkable disparity ; specimens believed to be 
male and female have been received from Albania, and also from 
Portugal. Dahlbom has placed the species included in the genus 
Ferreola in that of Salius, the true species of Salius being ap- 
parently removed into a new genus, Homotus. 
The species of the extensive genus Pompilus present so many 
phases of difference, that without types of every described species, 
it becomes impossible in a catalogue to arrange them in any 
more satisfactory order than that of locality; in arranging those 
belonging to the fauna of any particular country, the armature 
of the legs appears to afford the most constant character, and is 
one especially desirable, since it is a clue to habit. 
1. FERREOLA DIMIDIATA. B.M. 
Sphex dimidiata, Fabr. Ent. Syst. 11. 209. 45. 
Pompilus dimidiatus, Fabr. Syst. Piez. p. 189. 10. 
Van d. Lind. Hym. d@’ Eur. 322. 17. 
Ferreola Algira, St. Farg. Hym. ii. 468. 1. t. 36. f.19. 
Lucas, Explo. Sc. Alger. iii. 269. t. 14. f. 4. 
Hab. Algeria; Barbary. 
2. FerreoLA HuMBOLDTI. 
Salius Humboldti, Dahlb. Hym. Europ. i. 441. 
Hab. Egypt. 
3. FERREOLA SCHIODTEI. B.M. 
Salius Schiddtei, Dahlb. Hym. Europ. i. 441. 
Hab. Egypt; Cape of Good Hope; Port Natal. 
4, FERREOLA BICOLOR. B.M. 
Female. Length 7 lines.—Head, prothorax, mesothorax, scu- 
tellum and tegule ferruginous; the face fuscous; the meta- 
thorax truncate, deeply excavated, and receiving the base of the 
abdomen ; the legs, metathorax and abdomen cyaneous ; wings 
deep fuscous, the third submarginal cell much narrowed towards 
the marginal. 
Hab. Port Natal. 
This species closely resembles F. Schiddtei, but the prothorax 
is longer and the metathorax much more deeply excavated. 
