4 G. C. Crampton aiid W. H. Hasey, 



jecting- region tnl, of Figs. 8 and 9, is evidently a portion of the 

 trocliantin, since it forms one of the points of articulation with the 

 coxa, and is divided bj^ an oblique suture, as in the trochantin of 

 the roach (Figs. 1 and 2, tn). On the other hand, the region ac of 

 Figs. 8 and 9, is not a portion of the true trochantin {tn, of Figs. 2, 

 3, 22, etc.) for the t3^pical trochantin is never connected with the 

 sternal region. On this account, the region ac of Figs. 8 and 9 must 

 correspond to the narrow marginal region ac, of Figs. 1 and 2. 

 Furthermore, since the episternum (es, of Figs. 1 and 2) always 

 extends from the top to the bottom of the pleural plate, along the 

 pleural suture, g, that portion of the region ptn of Figs. 8 and 9, 

 bordering upon the pleural suture, g. must be the lower portion of 

 the episternum. In other words, if the suture marking off the 

 region ac of Figs. 1 and 2, be thought of as prolonged above the 

 base of the trochantin until it meets (or almost meets) the pleural 

 suture g, and if the suture between the trochantin and the lower 

 portion of the episternum were obliterated, we would have a com- 

 pound sclerite homologous with the composite region designated as 

 2)tn in Figs. 8, 9, and 13. This composite sclerite ptn, is therefore 

 made up of the region ac, the trochantin, and the lower portion of the 

 episternum, and therefore cannot be designated as the trochantin alone. 

 It has been designated as the "pleurotrochantin" in a previous paper 

 (Cramptox, 1914) and this term will be retained in the present paper. 

 Some investigators regard tlie region ptn (Figs. 8 and 13) as the 

 trochantin alone (Figs. 1, 2, 3, and 22, tn). They are consequently 

 forced to make the unwarrented assumption that the small region 

 aes of Figs. 13 and 8, represents the entire episternum es, of 

 Figs. 1, 2, 3. etc.! The episternum (or its homologue) however, 

 alwaj's extends from the top to the bottom of the pleural plate, 

 along the pleural suture. On the other hand, it is not un- 

 common for both episternum and epimeron to become divided into 

 an upper and lower region, by the formation of secondary sutures, 

 as is the case in 31antispa (Fig. 13). And lastly, in the roach 

 Ischnoptera (Fig. 2) the sclerite es, which everyone admits is the 

 true episternum, is marked off into an upper region acs (Fig. 2), in 

 every way homologous with the region aes of Figs. 8 and 13. These 

 facts and a study of the musculature, can lead to no other conclusion 

 but that the region aes of Figs, 8 and 13, is merely the upper 

 portion of the episternum, called the anepisteruum, while the region 

 ptn of Figs. 8 and 13, is a composite sclerite, composed of the lower 



