SUBFAMILY TRYXALINAE 19 
acuminate, and are scarcely longer than the head and pronotum. The 
pronotum has the lateral and median carinae distinct and cut only once, 
decidedly behind the middle, by the principal sulcus. Besides the three 
usual carinae there are two supplementary carinae, one on either side 
of the median and lower, or obsolescent, at the principal sulcus. The 
posterior margin of the pronotum is very obtusely angulate. The lobes 
of the pronotum are about as high as long, with the anterior border 
decidedly more oblique than the posterior. They bear a more or less 
distinct carina, which runs obliquely downward from the first sulcus 
to or near the posterior margin. The anterior lower angle is obtuse 
while the posterior is nearly rectangular. The lower margin is straight 
and nearly horizontal on the posterior half and slightly ascending on 
the anterior half. The mesosternal lobes are separated by a space 
much wider than long and the metasternal lobes by a space longer 
than wide in both sexes. The wings are usually well developed in both 
sexes. There is no intercalary vein and the dividing vein is soon 
united with the plicate vein. The ovipositor of the female is nearly 
included. The posterior femora are stouter than is usual in this group, 
with the tip extending more or less beyond the end of the abdomen; 
they are not marked with cross bands but the colors are sometimes 
arranged in longitudinal bands. Posterior tibiae are usually obscurely 
colored in yellowish or clay but never blue; the inner apical spur is 
about twice as long as the outer. The genus includes small, variously 
colored, active insects which may be readily distinguished by the 
supplementary carinae and the oblique carina upon the lobes of the 
pronottm. But one species has, as yet, been taken within our area. 
Eritettix tricarinatus Thom. 
Eritettix tricarinatus occurs, with us, in two distinct color forms, 
most commonly of a brownish tone with the dorsum and tegmina 
marked with black spots, but sometimes of a bright green general 
color, similarly marked. It has been noted as rather common in early 
spring on high gravelly hills in Ottertail County. We have taken it 
there as early as May 1, and it is numerous until near the middle of 
July. Hibernation carries it through the winter in the immature stages 
and mating and oviposition occur in early summer. As with most 
related forms, the males are much smaller than the females but similar 
in general appearance. It is a very alert and active little insect and 
the pale color, small size, and active habits make it a very hard subject 
for close observation in the field. The green form somewhat resembles 
Orphulella speciosa Scudd. in the field, although the clubbed antennae 
and the supplementary carinae readily distinguish it from that species. 
