156 PEOCEEDINGS OF THE NATIONAL MUSEUM vol.75 



and in some species more than half, of the total width of the front 

 aspect of the head ; anterior ocellus reduced to a linear, transverse, 

 arcuate cicatrice; clypeus prominent, bulging, in some species, when 

 viewed from the side, resembling a blunt nose; mandibles edentate; 

 maxillary palpus composed of three segments, labial of one; first 

 intercubitus straight ; metacarpus at its apical end not confluent with 

 the anterior margin of the wing; posterior-lateral angles of propo- 

 deum rounded, its posterior, dorsal, median border somewhat promi- 

 nent and overhanging somewhat the slightly excavated posterior 

 surface of the segment ; second sternite of male usually provided with 

 a more or less well developed median process; eighth sternite ending 

 in a single spine ; spatha of male genitalia as in Figure 57. 



KEY TO SPECIES OP MICEOBBMBEX 



1. Males (visible segments in abdomen 7; segmrents in antenna 13) 2. 



Females (visible segments in abdomen 6; segments in antenna 12) 7. 



2. Seventh tergite bearing distinct lateral spines bidens. 



Seventh tergite without lateral spines 3. 



3. Hind femur near middle point distinctly widened, forming rounded obtuse 



angle on posterior border (fig. 49) sulphurea. 



Hind femur not thus developed 4. 



4. Seventh tergite with evident rounded lateral angles, best seen in ventral 



view (fig. 54) tricosa. 



Seventh tergite not so developed 5. 



5. Process on second sternite long and curved (fig. 64) ; clypeus, large spot on 



mesopleura, and large discal spots on scutum, yellow aurata. 



Process on second sternite otherwise; above combination of maculations not 

 present , 6. 



6. Process on second sternite blunt and hirsute (fig. 66) hirsuta. 



Process on second sternite otherwise monodonta. 



7. Sixth tergite at base with distinct lateral spinelike angles natalis. 



Sixth tergite without basal lateral angles 8. 



8. Anterior metatarsus with eight spines bidens. 



Anterior metatarsus not with eight spines 9. 



9. Posterior apical angle of anterior metatarsus not extended in form of promi- 



nent lobe; apical emargination of clypeus ellipsoid in form (fig. 61). 



nasuta. 



Posterior apical angle of anterior metatarsus extended in form of prominent 



lobe; apical emargination of cl5T)eus arcuate in form (fig. 9) 10. 



10. Anterior metatarsus with seven spines ; second abscissa of cubital vein equal 



in length to second abscissa of radial ; length 15 mm equalis. 



Anterior metatarsus not with seven spines ; second abscissa of the cubital 

 vein not equal in length to second abscissa of radial 11. 



11. Fasciae on tergites bicolored, yellow dorsally, pale or creamy colored later- 



ally (Jamaica) tricosa. 



Fasciae on tergites uniform in color, yellow or pale 12. 



12. Pubescence on head, thorax, and propodeum unusually long and dense, very 



conspicuous on dorsum and lateral angles of propodeum hirsuta. 



Pubescence not unusually long and dense 13. 



