OF WASHINGTON. 105 



The mesothorax bears the elytra-like front wings, and a com- 

 parison of fig. 15 with fig. 19, representing the mesonotum of 

 Spongophora and of Calosoma respectively, will show more 

 points of resemblance than would a comparison of the euplex- 

 opteran mesonotum with the mesonotum of any orthopteron. 

 There is present in Spongophora (fig. 15) the triangular me- 

 dian shield with its apex projecting over the posterior margin, 

 and the elytral articulation is very suggestive of that of the 

 beetles. There is an extra piece {d) present, however, which 

 extends to the edge of the epistemum, but this may be the 

 parapteron, for otherwise mesothoracic paraptera are absent. 

 Opposing this view is a corresponding sclerite (figs. 11 and 12, 

 e) in the metathorax where both paraptera in addition are 

 present. The ventral surface of the mesonotum (fig. 14) is 

 very simple, presenting simply a median ridge, an anterior 

 phragma {Ph), and a posterior reduplication (Rd). 



The mesopleurum (fig. 9) is sufficiently shown by the illus- 

 tration. It has all the parts of a perfect pleurum except parap- 

 tera. In Coleoptera the mesothoracic paraptera are always 

 reduced, generally rudimentary, and often lacking, while in 

 winged Orthoptera these plates are almost invariably present. 



The metathorax differs strikingly from the mesothorax. The 

 notum is large and irregular (fig. 18), composed of a main 

 triangular plate (N) with its apex posterior, and of two bars 

 (/) articulated to the apex of this plate and extending outward 

 and posteriorly. The latter support the axillary regions of the 

 wings and are followed by a free fold of membrane (g) which 

 is the true caudal margin of the notum. The main notal plate 

 presents dorsally a wide median groove (G) bordered on each 

 side by a row of closely-set recurved spines. This groove re- 

 minds one of the groove of the coleopteran metanotum. 



Behind the free membranous posterior edge (g) is a large 

 pseudonotum partially divided into two plates by an imperfect 

 median suture. This is a prominent coleopteran character. 

 The plate can hardly be interpreted as an abdominal notum be- 

 cause the large first-abdominal spiracles (Sp) are attached to 

 the following sclerite, evidently the true first-abdominal notum 

 (/. Ab. N). 



The metapleurum has a remarkably coleopteran appearance 

 (figs. II and 12). In the first place the pleural suture (PS) is 

 horizontal, and the episternum is much larger than the epimerum 

 and is widest in front. The wing process (WP) is a slender 

 continuation of the pleural ridge (PR). Though there are 

 two paraptera present (iP and 2F), the second is small, while 

 the other is large, partially fused with the episternum, bears 



