Ml'. R. E. Turner on Fossorial Hymenoptera. 93 



differently formed from the others, the mandibles less dis- 

 tinctly trideutate, and a spine on the anterior femora of the 

 male ; the second joint of the flagellum is also very long. 

 C. ordinarius, manifestalus, bivittatus, and negledus form 

 another gi'oup nearly related to the last; whilst C. con- 

 glohatus and cinctus have the male antennae normal and no 

 carina on the clypeus. In the two latter species and in 

 hebeiescens the tooth on the inner side of the mandibles 

 near the base is well developed, which, so far as I can see, is 

 not the case in the other species. 



Key to the Australian Species o/Crabro (Solenius). 



22- 



1. Clypeus with a carina 2. 



Clypeus without a carina 8. 



2. ^Vith an orange or yellow band, entire or 



interrupted, on tiie base of the second 



dorsal segment 3. 



Without an orange or yellow band on the 

 second dorsal liegnient 7. 



3. Clypeus produced into a strong porrect tooth 



at the apex, with a tooth on each side at 



the lateral angles 4. 



Clypeus not produced into a porrect tooth, 

 lateral angles without teeth 5. 



4. Transverse band of second dorsal segment 



orange, broad, and entire ; three apical 



segments orange C. tridentatus, Sm, 



Transverse baud of second dorsal segment 

 yellow, narrow, and interrupted ; basal 

 half of fourth dorsal segment yellow; 

 two apical segments black C. ttmncmicun, Sm. 



5. Fourth dorsal segment with a transverse 



orange or yellow band at the base .... 6. 



Fourth dorsal segment entirely black C. manifcstatus, Turn. 



(j. Band of the second segment orange and 

 broad ; scutellum and postscutellum en- 

 tirely black C. hivittatus, Turn. 



Band of the second segment yellow and nar- 

 row ; scutellum with a yellow spot at 

 the basal angles, postscutellum with a 

 transverse yellow band C. ordinarius, Turn. 



7. Second dorsal segment entirely black C. mackayensis, Turn. 



Five basal dorsal segments with lateral 



white spots C. hebetescens, Turn. 



8. Clypeus with a small semicircular trunca- 



tion at the slightly porrect apex ; ante- 

 rior angles of pronotum pointed ; three 



apical dorsal segments orange C. anctiis, Turn. 



Clypeus without an apical truncation, not 

 porrect ; anterior angles of pronotum 

 obtuse ; three apical dorsal segments 

 black C. conr/lohatuS) Turn. 



