152 PROCEEDINGS OF THE ACADEMY OF 



Metathorax and abdomeu entirely yellowish red : 

 Head, pro- and mesotliorax, and scutellum black and Tvliite. 



24. perteniiis. 



Head black, thorax reddish 2o. collaris. 



Head, thorax, and abdomen entirely black ; four anterior legs and liind tarsi 

 pale 2G. arctus. 



1. Mesostenus aztecus, n. sp. 



9. Black; face, clj'peus, spot on mandibles, anterior orbits, 

 cheeks, broad annulus on antennae, collar, tegula?, line in front, 

 spot beneath, spot on disk of mesotliorax, apex of scutellum, two 

 oblique lines in front, postscutellum, mark behind base of wings, 

 two elongate marks on posterior face of metathorax from spines, 

 covering them, to apex, a large mark on flanks, a large subcunci- 

 form mark on each side of pleura and two subquadrate spots be- 

 neath, whitish; wings hyaline, apex dusk}-, nervures black; legs 

 luteous-yellow, posterior coxre hone^'-yellow, four anterior coxre 

 and base of posterior pair whitish, all the femora within, posterior 

 knees and extreme tips of tarsi, black; abdomen black above, base 

 and apex of first segment, apical margins of the following segments, 

 and a spot on each basal corner of second segment, white or ^-el- 

 lowish-white. Large, elongate, robust, thorax opaque, abdomen 

 shining; upper lateral angles of prothorax subtuberculate ; meta- 

 thorax transversel}' striated behind, the spines prominent, obtuse 

 and slightly recurved; areolet subquadrate, narrow, closed. 

 Length 8 lines. 



Cordova. (Sumichrast, Xos. 62 and 55.) 



2. Mesostenus propinquus, n. sp. 



9 ^Marked like azlecus. except tliat the two apical white marks 



on raetatliorax are continued for a short distance above the spines, 

 which are not recurved at tip ; the pleura is cntirel}' black beneath, 

 the lateral spot with a slender hook beneath, projecting forward; 

 the posterior coxjb are white, with a broad black mark on outside 

 and a smaller one within ; the abdomen is more robust, the first 

 segment shorter and more squarely dilated at apex ; the upper 

 lateral angles of prothorax are not prominent. Length G-7i 

 lines. 



% Antennae rather longer than body; posterior legs very 

 long, with tips of their tibije black; abdomen short, narrow, the 

 first segment black, with a narrow central mark and apical margin 

 pale; otherwise like ?. Length 7 lines. 



Cordova. (Sumichrast, No. 78.) 



