312 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 
The mesopleurites (Fig. — ) are very oblique. The episternum is di- 
vided into two sclerites, the upper one third as long as the lower and 
scale-like; the lower oblong, uarrow, very long, and on the sternal 
margin bent down next to the sternite. The epimerum is divided into 
a long, narrow, linear, cliitinous portion next to the episternum, the 
posterior portion lying in front of the metathorax. 
Between the lower end of the episternum and coxa is a small, trian- 
gular sclerite which I suppose is the trochautine. The coxa is very 
large, long and quadrangular. 
Metapleurites as the mesopleurites, but the sub-episternum is a little 
wider, and the sur-episternum is longer, while the epimerum is almost 
wholly membranous. The trochautine? is more distinct than in the 
mesotliorax. The coxa is of the same form as in mesotliorax, but a 
little thicker. 
Sternum. 
The prosternum (Figs. 1-3) is divided into a prae- and poststernite, the 
latter remarkably long. 
The mesosternum is narrow, triangular, flat ; the apex bordered on each 
side with a lateral sternal fold of the integument. 
Metasternum. A large part of the sternal surface is occupied by the 
sternal portions of the episterua, which are bent beneath the body. 
The sternal area is broader and longer than in the mesosternum, but the 
limits of the sternite itself are less definite ; it appears to be a long, 
narrow, lanceolate-oval area (but this part needs further comparative 
study, with more material in species than we possess). 
* THE ABDOMEN. 
There are ten segments or uromeres, with ten tergites. The cerco- 
poda arise from the tenth segment. They are stout, many jointed, and 
much as in Blatta, only longer. There are but six urosternites. The 
eight pairs of stigmata are situated on the membranous pleurites. 
Remarks. Mantis is a genuine Orthopter in venation as well as in 
the fundamental structure of the body, and is truly intermediate in its 
structure between the Acrydii and the Blattariae, approximating the 
latter in the structure of the head, mouth-parts, prothorax, the shape 
of the abdomen, and its appendages. Blatta, in part, may be regarded 
as the ancestral or stem form of the Orthoptera, from which all the 
other Orthoptera may have descended; and this accords in the main 
with the geological succession of the different Orthopterous families so 
far as we know it. 
Phasmida. • 
THE HEAD. 
Diapheromera femoratum. Pupa. The head (PI. XXV, XXVI) is 
small, narrow, nearly horizontal, subcylindrical. The epicrauium is 
