NATURAL SCIENCES OF PHILADELPHIA. 159 



abdomen black above, first segment except a subapical spot, 

 narrow lateral and broad apical margins of second and following 

 segments and an acute ovate spot on basal middle of second seg- 

 ment, white. Slender, opaque ; mesothorax coarsely and conflu- 

 ently pitted ; nietatborax rugose, tubercles flat and obtuse ; ab- 

 domen smooth, slender; areolet 5-angular, open. Length 5 lines. 

 Cordova. 



17. Mesostenus accolens, n. $p. 



9. Black; face, mouth, broad orbits, annulus on antennae, 

 collar, tegulae, broad line in front, spot beneath, two short discal 

 lines on mesothorax, scutellum, two oblique spots in front, dot 

 on postscutellum, pleura and space behind base of wings, white ; 

 raetathorax tinged with honey -yellow, tubercles whitish, a broad 

 central stripe dilated at base, and a narrow basal stripe on each 

 side, black ; wings faintly dusky, nervures fuscous; legs honej'- 

 yellow, four anterior coxiB and spot at base of posterior pair 

 paler, four anterior tarsi dusky, posterior pair white, black at 

 base and apex ; abdomen black above, base of first segment 

 honey-j'ellow, apical margin of all the segments rather broadly 

 white, becoming narrower on apical segments. Opaque, thorax 

 and abdomen smooth, metathorax coarsely rugose, tubercles flat, 

 obtuse ; areolet very small, quadrate, open ; abdomen slender at 

 base, remainder oblong-ovate. Length 4^-5 lines. 



Mirador. 



18. Mesostenus novatus, n. sp. 



5. Much like accolens, but differs as follows: The anmilus on 

 antennae broader ; metathorax longer, the distance between base 

 and tubercles greater, the broad black central mark is subcruci- 

 form, and confluent with a triangular spot at base ; posterior coxae 

 entirely honey-yellow, their tarsi yellow at base and black at tips ; 

 first abdominal segment with the subapical spot continued to base 

 in a slender line ; areolet 5-angular, open ; abdomen more elongate 

 and narrow. Length 5^ lines. 



Mirador. 



19. Mesostenus stupidus, n. sp. 



9 Black; face, mouth, orbits, narrow annnlns on antennae, 



collar, tegulae, line in front, spot beneath, two long longitudinal 

 lines on mesothorax interrupted by the impressed lines, scutel- 

 lum, spot on postscutellum, spot beneath wings, space behind 



