320 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 
Metanotum. On the same plan as the mesonotum, but about three 
times as long; the scutum is very short and slightly depressed in the 
middle, enlarging and swollen on the sides. The scutellum is of the 
same shape as in the mesonotum, but mucl* larger; behind it is a mod- 
erately broad, flat band, representing the postscutellum. 
Pleurum. 
Propleurum. In the prothorax the episternum is represented by two 
small sclerites, one forming a spine. The epimerum is minute, rudi- 
mentary, submembranous. The coxa and trochantine are consolidated 
into a single, large, thick coxal joint. The prostigmata are rather large 
and situated on a distiuct peritreme. 
Mesopleurum. The episternum is divided into three sclerites, the upper 
much larger than the two lower sclerites, and triangular, with the apex 
produced towards the insertion of the wings, but not extending up so 
high as the epimerum. Of the two other sclerites one is supracoxal, and 
the other is next to the sternum. The epimerum is a large, lanceolate- 
oval, scale-like, single sclerite, with the posterior edge free, below which 
is the mesostigma. 
Metapleurum. This is much larger than the pleurum of the meso- 
thorax. The episternum is large, oblique, narrow triangular, with the 
apex extending as far as the upper end of the epimerum; the latter is 
quite wide, narrowing below ; the hind margin is not, however, free. 
Sternum. 
Prosternum. This is in part rudimentary, and consists of a transverse 
row of three small sclerites surrounded by membrane, behind which 
are two larger sclerites, and above, on each side, is a subtriangular piece. 
Between the coxae, which are wide apart, is a small, triangular sternite, 
which sends off long, chitinous angles towards the episternal spines. 
Behind this is a narrow, long, scutel-like sclerite. 
Meso- and metasternum. These are both large, broad, solid sclerites, as 
long as broad, augulated obtusely on the sides, and notched in the mid- 
dle of the posterior rnargiu, especially on the metathontx. 
THE ABDOMEN. 
There are eleven uromeres : eleven tergites, the lltli being the supra- 
anal plate; the 10th is narrower than the 9th, and situated between the 
cercopoda, which are large and long and obscurely jointed. The 11th 
tergite is separated by a faint suture from the 10th tergite. The pleural 
region is rather broad, bearing the eight pairs of stigmata. There are 
eight well developed urosternites; the 7th is twice as long as the basal 
seven. The 8th is small and rounded behind. 
THE HEAD. 
Gryllotalpa borealis. The head and prothorax are admirably adapted 
to the fossorial habits of this insect. The head is loug, and rounded 
