No. 417.] 
NORTH-AMERICAN INVERTEBRATES. 747 
J2. The two posterior lateral spines equal 
B. (or Schizocerca) diversicornis, var. homoceros Wierz 
e2. Four variable (often subequal) anterior spines or teeth. 
Anterior ventral margin of lorica sinuous. Posterior part of 
the lorica rounded, either without teeth or with two or four 
teeth or spines. (Excessively variable) . 145, B. pala Ehr. 
JT. Median anterior spines very d no posterior spines 
B. pata, var. dorcas Gosse 
f2. Median anterior spines Pic long ; two marked posterior 
spmes . . B. pala, var. spinosus Wierz. 
23. Four anterior spines — about equal length. Lorica sub- 
quadrate in dorsal view ; thick, so that a transverse section 
would be nearly a circle. A slight invagination in the sides 
of the lorica in the lumbar region, causing blunt angles on 
the sides of the lorica. Entire surface covered with minute 
spinules. No posterior spines 
B. punctatus Hempel (Fig. 104) 
140, 
d3. Anterior margin of lorica without teeth or spines ; at most 
c3. 
merely sinuate 
eZ. Anterior dorsal margin sinuate, with a slight rounded notch 
in the middle. Lorica usually with irregular bluntly angled 
outlines and with faceted surface. Posterior extremity with 
two short blunt processes close to the foot 
7, B. angularis Gosse 
Jt. The two posterior aee draia into spines 
B. angularis, var. bidens Plate 
e2. Anterior dorsal margin straight and truncated, with a 
small median sinus for the dorsal antenna; lorica thin, 
smooth, flexible. Dorsal surface highly arched; ventral, 
nearly flat. Toes pointed, and having the inner edges convex, 
the outer concave . . . 148, B. mollis Hempel (Fig. 105) 
Foot ending in two toes, and situated on the ventral side o 
the body ; lorica an irregularly oblong or ellipsoidal box, marked 
with grooves and sometimes with ress closed behind, opened 
ventrally for the protrusion of the foo à Ploesoma 
dr. Lorica firm, with two wide et benedi ies ridges 
passing transversely across the middle of the dorsal surface ; a 
number of deep longitudinal grooves passing forward and back- 
ward from the ends of the transverse grooves ; surface covered 
with fine areolations. Lorica in dorsal view about twice as long 
as wide, projecting at the anterior dorsal margin in a sharp 
median point, flanked by two small points or angles 
149, P. lenticulare Herrick (Fig. 106) 
42. Body short, little longer than wide ; lorica with grooves and 
ridges much as in the last, but more thin and flexible, and not 
