148 THE CANADIAN ENTOMOLOGIST 



the ventral edge of the pronotum. It tapers posteriorly to a point which is 

 attached near the posterior ventral angle of the pronotum. 



Much the same conditions are found in the other Acridiidae examined, viz., 

 Melanoplus, Dissosteira, (Fig. 3) Stenohothriis, Chortophaga, Camniila and 

 Acridium. 



The TettigidcB. (Figs. 4 and 5). 



Tettix granulatus. A notch in the edge of the pronotum exposes a very- 

 small portion of the ventral edge of the episternum (Fig. 4, est). Internally 

 the appearance is similar to that of the Acridiidae. The episternum narrows 

 more abruptly and the epimeron is shorter and more narrowed posteriorly. 

 The entopleurite is thin and quite deep. The entosternal arch (Fig. 5, ents.) 

 fuses with the entopleurite near its dorsal end and not, as in the Acridiidae, 

 near the ventral end. 



The LocustidcE. (Figs. 6, 7 and 8). 



Conocephalus (Fig. 6). Externally a very small, triangular portion of 

 the episternum may be seen lying cephalo-laterad of the coxa. The greater 

 portion of this sclerite, however, lies on the inner side of the pronotum extend- 

 ing more than half way towards the dorsal median line. The anterior edge is 

 inflexed slightly and almost parallel with the posterior edge; the dorsal edge is 

 rounded. The entopleural ridge projects ventrally and articulates with the 

 coxa. At the dorsal end of the pleuron the epimeron is represented by a very 

 small, narrow sclerite. At the ventral end there is a short, narrow, rod-like 

 sclerite projecting backwards in much the same position as the epimeron in the 

 Acridiidae but very much more reduced. 



The pleural regions of Xiphidium are very similar to those of Conocephalus. 



Microcentrum (Fig. 7). Here the episternum is triangular, tapering 

 dorsally. The epimeron is very narrow and, as a free sclerite, is confined to 

 the dorsal half of the pleuron. It projects dorsally some distance beyond the 

 episternum. 



Ceuthophilus maculatus (Fig. 8). The episternum is broad and deeply 

 bilobed. The entopleural ridge is strong and curved; the epimeron is 

 very narrow, widest at the dorsal end and extending almost to the ventral edge 

 of the pronotum. 



The Gryllidce. (Figs. 9, 10, 11). 



Gryllus pennsylvanicus (Figs. and 10). The pleuron extends dorsad 

 almost to the ntedian line. It is irregular in shape, and as it follows the curve 

 of the pronotum is itself pronouncedly curved. The episternum is narrow 

 but well developed, and the ventral edge projects slightly below the pronotal 

 edge. The entopleural ridge is deep and projects ventrally, articulating with 

 the coxa by a ball and socket joint. The epimeron is narrow and is best de- 

 veloped dorsally. It does not descend as far as the ventral edge of the pronotum . 



(Ecanthus nigricornis (Fig. 11). In (Ecanthus the pleuron is completely 

 overgrown by the pronotum. The anterior ventral angle projects slightly 

 beyond the membranous integument (shown by the dotted line) connecting 

 the pronotum and the sternal sclerites, so this small portion of the episternum 

 can be seen on the ventral side beneath the flange-like edge of the pronotum. 

 The episternum is broadly oblong. The entopleural ridge is narrow and but 



