3fi 
The Rocky Mountain Locust— ( Caloptenus spretus )—Thos. 
Female. The face nearly perpendicular, sloping under toward the 
breast very slightly. The vertex between the eyes the same width as 
the frontal costa just above the ocellus; that portion in front of the 
eyes more or less distinctly channeled, and deflexed at an angle of about 
40 degrees from horizontal. Eyes nearly straight in front, about semi¬ 
circular behind. Antennae quite slender, reaching little if any beyond 
the tip of the pronotum. Pronotum, with the sides of the anterior 
lobes parallel, the posterior lobe expanding rapidly backward; median 
carina thread-like, but always distinct on the posterior lobe, usually 
obsolete on the anterior lobes; lateral carinae obtuse but distinct on 
the posterior lobe and usually so on the middle one but becoming ob¬ 
solete toward the front; posterior lateral margin, perpendicular irom 
the humeral (entering) angle one-third the w r ay down, then curving 
forward to the posterior lateral angle which is obtuse and rounded; 
the (entering) humeral angle is sharply defined, and in this respect 
differs from C. jemur-rubrum and C. atlanis; the apex is obtuse-angled 
(about 100°) rounded at the point; posterior lobe minutely and shal¬ 
lowly punctured throughout; the anterior lobes smooth with few or 
no punctures except along the lower margins of the sides. Elytra 
and wings extending beyond the tip of the abdomen from one-fourth 
to one-third their length; the elytra are of nearly uniform width 
throughout, slightly curving upward at their extremity; wings a lit¬ 
tle shorter than the elytra, very thin and delicate ; nerves and ner- 
vules very slender. Abdomen, and in fact the whole insect rather 
more slender than usual in this genus; but this appearance is partly 
due to the elongated wings ;cerci very small, triangular or tooth-shap¬ 
ed, not extending across the segment on which they rest; valves of 
the ovipositor quite prominent, especially the upper pair which are 
more than usually exserted, sharp at the tips and deeply excavated 
above. The posterior femora usually extend to or about to the tip of 
the abdomen. 
Color. —Reddish-brown with fuscous spots. Head and the prono¬ 
tum back to the posterior sulcus reddish-browm, varying in depth of 
color in individuals ; the face is sometimes of a lighter and brighter 
red than the pronotum, sometimes darker, assuming a dark purplish 
hue; the posterior lobe of the pronotum is generally a pale olive- 
brown, its lighter color contrasting somewhat distinctly with the 
darker shades of the anterior portion. Some individuals exhibit much 
lighter colors than here described, varying from a dark-brown to a 
dull yellow. The dark line on the side of the head and pronotum, 
usually so conspicuous in the closely allied species, is generally oblite¬ 
rated in this species by the dark-brown color ; but it usually appears 
distinctly in specimens which have been immersed for some time in 
alcohol, and is also manifest in the pale individuals, but is broken uj> 
by pale spaces and lines, and is rather narrow ; the eyes shining- 
black ; elytra ash-brown, more or less tinged with reddish-brown at 
the base and fading toward the apex; in the middle field, commencing- 
near the base, w T here this field comes to a point, is an irregular row of 
