OBTHOPTERA. 
317 
THE THORAX. 
Notum. 
Pronotum. (PI. XXVIII.) The prothorax is remarkably long, cylin- 
drical, and full iu the middle. It is very singular for having no sternum as 
distinguished from the tergum, but the segment is perfectly cylindrical, 
with only a tine, lateral, straight suture, which is obsolete behind the 
legs; while along the sternal region behind the legs there is a median, 
flue suture. The episternum is present, but no epimerum is differ- 
entiated from the tergum. The anterior spiracles are situated on the 
front edge of the mesotborax, and these are really the usual prothoracic 
ones, .while there is another pair on the hind edge of the mesotborax on 
the rudimentary mesepimerum. 
The mesonotum (PI. XXX) consists of a single oblong sclerite, one 
third longer than broad, very slightly separated from the pleurum; the 
surface is rounded and rough like the rest of the segment. 
The metanotum (PI. XXX) consists of two portions which have no re- 
semblance to a scutum and scutellum, but which are separated on the 
side by a diverging ridge extending down the sides into the epimerum ; 
the anterior area is short, transversely broad, while the posterior area 
is not separated by suture from the anterior, but is as long as broad, 
and rounded in front. It is interesting to notice the extreme modifica- 
tion of the meso- and metanotum, owing to the absence of wings, and 
also those characteristics due to the cylindrical form of the body. Pros- 
copia is a link between the Acrydii and the Phasmida. 
Pleurum. 
The mesopleurites (PI. XXXT) are well marked sclerit.es, but are still 
subordinated in form and relation to the cylindrical form of the body. 
They are oblique, separated by a fine suture from the tergum. The epi- 
sternum is large and broad, irregular in shape, while the epimerum is 
much shorter, and not much longer than wide. The pro-peritremes, 
bearing the prostigmata, are separated by suture from the prothorax, 
and the meso-peritreme is consolidated with the posterior edge of the 
mesepimerum. 
The meUrpleurites (PI. XXXI) are much as in the mesotborax, but shor- 
ter. The episternum is straight-edged; though oblique in its general 
position, it is as wide as in the mesotborax, while the epimerum is less 
than half as wide as the mesepimerum, aud the upper portiou is reduced 
to a mere ridge, which extends upon the notum. The metacoxae are as in 
Diapheromera, being twice as large as those of the mesothoracic segment, 
while the procoxm are a little smaller than those of the metathorax. 
Sternum. 
The sternites (PI. XXXII) are broad pieces, the meso- and metaster- 
nites not separated by suture. The external openings of the mes-euto- 
