LOCUST RAVAGES IN CALIFORNIA. 
243 
try, is divided into three groups, Truxalmi, Acrid/mi, and CEdipodini, 
the migratory species being confined to the second and third, which are 
distinguished from each other by the presence or absence of a prosternal 
spine or tubercle, thus : 
To the former group belong most of the migratory species, to wit : 
Acridium peregrinum, A. paranense, A. americanum (if this is the Central 
American locust, which is doubtful), Caloptenus italicus, and G. spretus. 
To the latter belong Pachytylus migratorius and Camnula pellucida. 
The former of these two species, which is large, measuring about two 
inches in length, is found only on the Eastern Continent ; the latter, 
which is comparatively small, is found only in North America. 
The genus Camnula, which was established by Stal, is, according to 
that author, distinguished from other genera of the same group by the 
following characteristics : 
The fastigium of the vertex slightly defiexed, rather narrow ; seen from the side it 
forms an obtuse angle with the frontal costa, concave, not carinated (that is, without 
a, median carina), nor terminated posteriorly by a carina, but in fact by a slender 
transverse impression ; frontal costa slightly sulcatc, distinctly narrowed below the 
ocellus ; the pronotum with the lateral margins distinctly carinated ; the (posterior) 
sulcus divides the median carina, but is usually interrupted by the lateral carinas 
which are usually severed by the middle or anterior sulcus ; the posterior lobe is dis- 
tinctly longer than the anterior surface, not granulated or rugose. 
CEdijyoda pellucida Scudd., Bost. Jour. Nat. Hist. VII, 1862. 
atrox Scudd., Hayden's Geol. Surv. Neb., 253. 
Camnula tricarinata Stal, Recens. Orthop., 1873. 
In order that the reader may judge for himself in reference to the 
identity of the species, we give here the three original descriptions. 
CE. pellucida Scudd. 
Ash-brown ; face reddish brown ; antennae* yellowish at base, dark brown toward 
tip ; a triangular black spot behind the eye, the apex touching it ; a quadrate trans- 
verse black spot on the anterior upper portion of the sides of pronotum ; pronotum 
above, sometimes with a dark band down the middle ; wing covers with the basal half 
dark brown, with small yellowish spots and transverse streaks, especially on front 
border; apical half clear, with dark brown rounded spots, prevalent along the middle, 
decreasing in size toward the tip ; when closed the upper surface is dark brown, with 
a rather broad yellowish vitta along each angle on the upper surface ; wings pellucid, 
with black nervules; legs dark brown, the hind femora yellowish or reddish brown, 
with two or three rather broad diagonal dark brown streaks, dark at the apex ; hind 
tibiaa yellowish brown, reddish toward the tip, with a very narrow, generally faint, 
annulation of dark brown at the base ; spines tipped with black. 
Length of body : male .65 inch, female 1 inch ; spread of wings : male 1.3 inches, fe- 
male 1.6 inches ; depth of wings : male .33 inch ; female .4 inch. 
CE. atrox Scudd. 
Head uniform, pale brownish yellow ; the raised edge of the vertex dotted with fus- 
cous; a dark fuscous spot behind the eye, broadening posteriorly, but not extending 
a Presternum or front breast armed with a spine or tubercle 
aa Presternum unarmed 
Acridiui. 
CEdipodini. 
CAMNULA PELLUCIDA. 
