486 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
the angle rounded. Mid-carina of pronotum on metazone only. 
Metepisternum with pale streak. Hind femora fasciate. 
Dawson's Locust, M. dawsoni, p. 516. 
nnn. Tegmina lanceolate, equaling or exceeding pronotum, bluntly 
pointed. Lateral lobes as deep as long; lateral stripe wanting or 
but faintly indicated. Body compressed. Mid-carina of pro- 
notum distinct throughout. Hind margin of pronotum decidedly 
extended, angulate. Metepisternum without pale streak. Hind 
femora not fasciate. 
Scudder's Short-winged Locust, M. scudderi, p. 520. 
mm. Hind tibiae green, gray, or bluish. 
0. Tegmina with bluntly rounded apex, equally as long as pronotum. 
Lateral lobes of pronotum much longer than deep; lateral stripe 
continuous or nearly so. Body not compressed. Head smaller, 
vertex projecting but Uttle. Ovipositor with scoop of upper valves 
relatively long, not angulated at base, and all valves very acutely 
pointed Green-legged Locust, M. viridipes, p. 522. 
00. Tegmina very acutely taper-pointed, distinctly longer than pro- 
notum. Lateral lobes nearly as deep as long; lateral stripe lacking 
on metazone. Body compressed. Head large, face strongly retreat- 
ing; vertex very prominent, projecting more than half the diameter 
of the eye. Ovipositor with scoop relatively short and angulated 
at base, and valves bluntly tipped. Head exceptionally large. 
Large-headed Locust, Phoetaliotes nebrascensis, p. 524. 
II. Tegmina much longer than pronotum. 
p. Large, robust; hind thighs 16 mm. or more long (usually 18 to 19). 
Dorsal area of closed tegmina separated from lateral area by a pale 
streak which sometimes suffuses entire dorsal area. 
Two-striped Locust, M. bivittatus, p. 514. 
pp. Smaller; hind thighs not over 14 mm. long. 
q. Lower valves of ovipositor about straight, the lateral tooth nearly 
or quite obsolete. Interspace between mesosternal lobes trans- 
verse. Tegmina maculate with dusky. Hind femora slender, 
fasciate externally, cherry red within at base. 
Pine-tree Locust, M. punctulatus, p. 511. 
qq. Lower valves of ovipositor with the apex more or less distinctly 
decurved and with a distinct lateral tooth midway of the lower 
outer margin. 
r. Tegmina usually passing end of hind thighs, body relatively 
slender, pronotum in side view often depressed at principal 
sulcus, with smaller, uninflated prozone. Interspace between 
mesosternal lobes longitudinal or quadrate, 
s. Tegmina more or less flecked with dusky and pale spots along 
the middle. Hind thighs usually showing more or less dis- 
tinct fuscous bands, at least on dorsal side. Upper valves 
of ovipositor angulated at base of scoop. 
