PROC. ENT. SOC. WASH., VOL. 24, NO. 1, JAN., 1922 19 



The epimeron of the mesothorax (epm2, fig. 18) in fissilis 

 Say suggests rather vaguely an anvil. Its short anterior 

 margin is transverse. The interior margin is divided distinctly 

 into a posterior and an anterior portion; the anterio-interior 

 portion is concave; the posterio-interior portion partially 

 closes the coxal cavity. The posterior margin is concave and 

 contiguous with the sternum and part of the episternum of the 

 metathorax. The exterior margin is thick and somewhat sul- 

 cate to receive the margin of the elytron; the outermost edge 

 of this marginal cleft combines with the anterior margin of the 

 sclerite to form an acute external angle. 



The coxae of the mesothorax are subspherical, rather large, 

 but not protruding (Cx2, fig. 17). 



METATHORAX. The notum of the metathorax (fig. 14) 

 is semi-membranous, and in communis Gyll., is subquadrate. 

 The scutellum (Scl, fig. 14) divides the scutum (set) by a narrow 

 median tongue extending forward from a more robust basal 

 scutellar area from which the axillary cord (AxC3, fig. 14) 

 extends on either side. Each longitudinal division of the 

 scutum is partially divided by a transverse suture into anterior 

 and posterior areas, the former of which bears the anterior notal 

 wing process (ANP, fig. 14), and the latter the posterior notal 

 wing process (PNP). The postscutellum or postnotum (PS, 

 fig. 14) is strongly transverse and partially divided by a broken 

 transverse suture. 



The sternum of the metathorax (St 3, fig. 17) is convex. In 

 .fissilis Say it is subquadrate, its anterior margin roundly 

 emarginated by the coxal cavities of the mesothorax. Its 

 lateral margins are straight and slightly divergent posteriorly. 

 The posterior margin is sinuate, acuminate at the middle with 

 the apex of the acumination finely emarginate. The. posterior 

 coxae (Cx3, fig. 17) are contiguous with the sternum along the 

 entire length of its posterior margin except for a separation 

 along the median line. The sternum bears a median longi- 

 tudinal impressed line which varies with different species in 

 depth and length; it may prove of taxonomic value in some 

 cases. 



Of the pleura of the metathorax only part of the episternum 

 (eps3, figs. 17, 19 & 20) is visible when the elytra are closed. 

 The entire episternum (fig. 19) in communis Gyll., is elongate 

 and roughly triangular; it ends anteriorly in the wing process 

 and parapterum (WP & P, fig. 19). The portion concealed 

 beneath the closed elytron is semi-corneous, while that part 

 ordinarily visible is oblong, about six times as long as wide, 

 and as heavily chitinized as the sternites. The two parts of the 

 episternum are separated by an impressed line, and the con- 

 cealed area is slightly depressed. 



The epimeron (epm3, figs. 19 & 20) of communis Gyll., lies 



