156 PROCEEDINGS OP THE ACADEMY OP 



orbits, tegnlae, line in front, spot beneath, spot on disk of meso- 

 tborax, scutelluras, two round spots at base of metatborax, flanks, 

 an elongate mark on posterior face broadly dilated at apex, most 

 of pleura, base and apex of first abdominal segment, apical and 

 lateral margins of remaining segments, and a triangular spot on 

 basal middle of second segment, all pale lemon-3'ellow ; broad an- 

 nulus on antennre white; wings hyaline, extreme apex dusk}', 

 nervures black ; legs j-ellowish-white, posterior tibise and tarsi 

 bright yellow ; stripe on outside of all the coxae, posterior pair 

 within, trochanters above, stripe on anterior femora above, double 

 stripe on middle pair and posterior pair except yellowish stripe 

 on outside, black; four anterior tarsi dusky. Form same as that 

 of cJiichimecus, shining, mesothorax strongly trilobate, sparsely 

 punctured; metathorax transversely rugose; abdomen smooth 

 and shining, sparsely punctured, seventh segment large, as in 

 chichimecus. Length 6 lines. 

 Orizaba. 



11. 'Mesostenus arcuatus, n. sp. 



9 Black; face, clj'peus, spot on mandibles, broad orbits in- 

 terrupted posteriorly, collar, teguhe, two very short lines before, 

 spot beneath, round spot on disk of mesothorax, scutellum, spot 

 on postscutellum, large mark on pleura, mark behind base of 

 wings, spot on flanks of metathorax, an arcuated line on pos- 

 terior face, and apical margins of abdominal segments, broad on 

 the three basal and very narrow on the remaining segments, 

 lemon-yellow; broad annulus on antennju white; legs pale yel- 

 lowish, the tibial and posterior tarsi briglit ^-ellow; spot on tips 

 of coxfe, four anterior femoia above and within, posterior pair 

 except broad stripe on either side and the four anterior tarsi, 

 black ; wings hA-aline, apex faintly dusky, nervures black. Sub- 

 opaque, metathorax obliquely truncate behind, without tubercles 

 or spines, the posterior truncation transversely rugose, the base 

 smooth and shining, and beneath the transverse carina a row of 

 radiating stria?; areolet small, 5-angular, outer nervure hyaline. 

 Length 5^ lines. 



Orizaba. 



12. Mesostenus admotus, n. i>p. 



9. Differs from aibmrandus as follows: The pale color more 

 whitish ; the metathorax broadly black at base, with a slender 



