WILLIAMS: LARRID^ OF KANSAS. 133 



dorsal and lateral division of the prothorax the neck, and the 

 more elevated posterior portion the collar. The pleural or side 

 sclerites (propleuron) are represented by the large episternum 

 (Eps) , which is partly covered by the overlapping pronotum. 



Mesothorax (2). This is the largest of the three thoracic 

 divisions. Dorsally it is composed of the convex scutum {Set) , 

 and the succeeding shorter piece, the scutellum (Scl) . These 

 combined constitute the mesonotum. From the anterior bor- 

 ders of the scutum, posteriorly, run the parapsidal furrows. 

 The scale-like tegulse (tg) which cover the base of the fore 

 wings are situated under the lateral edge of the scutum. The 

 pleural portion of the mesothorax consists of the large an- 

 terior episternum (Epn) and the more posterior epimeron 

 (Epm). The episterna do not meet on the mid-ventral line, as 

 do the epimera, for their whole length (fig. 4, Epm) ; there is 

 therefore no suture in this case separating the pleural from 

 the sternal portions. The mesosternum proper (S, fig. 4) is 

 situated caudal of the epimera and between the middle coxje. 



Metathorax (3). This is very small. Dorsally it consists of 

 the wing-bearing notum (N), behind which is the yet smaller 

 postnotum. The side of this segment (pi) is evidently not di- 

 vided into the two usual pieces by suture, such as exists in the 

 mesothorax. The small, grooved metasternum lies immedi- 

 ately behind the larger metasternum. 



Appendages of the Thorax. Wings. (PI. XXIV, fig. 14.) 

 The wings are inserted between the notal and pleural elements 

 of the mesothorax and metathorax, respectively, and inasmuch 

 as the fore wings are the chief organs of flight the mesothorax 

 is strongly developed at the expense of the inconspicuous 

 metathorax. 



The veins (fig. 14) and the cells (fig. 15, Tachysphex propin- 

 qmis) follow the usual nomenclature, the lettering being from 

 Fernald's Chlorioninse. The system is comparatively simple, 

 and while it may not be as logical as some others, it is easily 

 remembered and applied, and for that reason used here. An 

 enlarged figure of the inner margin of the primaries (pi. XXV, 

 fig. 33) shows the fold for the reception of the hooks on the 

 costal margin of the secondaries. One of these hooks is illus- 

 trated in figure 12. By this device the wings are united to 

 move in unison. 



2 -Univ. Sci. Bull.. Vol. VIII. No. 4. 



